There is always a fundamental overarching question to any efforts regarding urban revitalization. And that is the differentiation between "What Can Be Done?" and "What Should Be Done?" Ideally, these two should align and that is the trick. The 'Should' can often be too big of a bite to chew for many, especially sans willpower and money. Normally, one might say money is the biggest bite, but I disagree. It's usually when peoples are flush with money that they do stupid things with it. See: Dubai. It is precisely when money is hard to come by that competition of ideas is fierce and return on investment is critical.
With regards to Thanksgiving Square, it has a couple issues working against the remodel and repurposing of the space into something useful and less...ummm....pathological. First, it and its design is basically endowed. Then there is the more political issue, I suppose, of what we want the space to be. It is intended as a place of sanctity and isolation. A place to experience and perhaps meditate on how great Philip Johnson thinks he was. Unfortunately, it failed in all of these aspects and is used for smoke breaks and dog walks. Some of which is picked up. It is the only space I can think of that has a full-time attendant dealing with all of its varying maintenance issues, from mudslides, to dog poop proliferation, to clogged drains from the assortment of fountains, etc. etc.
All of these maintenance issues are symptomatic, of many things, but one in particular is the mistaken attempt to put a place of personal reflection in the middle of the city, where it will get overused and trampled. Sure, there is a place for such things, but then way make so many physical connections, to it, through it, and link subterranean space with surface space. It is a contradiction. At the same time trying to keep people out of it, while inviting people through it. It is not particularly pleasant, but as one of the few (semi-) softscapes in this part of downtown it will get used. And trampled.
Notice how many of the renowned urban plazas are little more than paving. It's the shape and scale of the space that makes it comfortable, but it is the location, the context, and interconnections that populate it. That drives demand, that fills the buildings, that activates the ground floor spaces. It is about the larger network and the space's place within that network.
We already know that it has both internal and external design flaws. It also is lacking in both internal and external demand drivers. (When I refer to external, I'm mostly referring to downtown as a whole.) Downtown can really only support a vibrant Main Street, which is little more than a functional, walkable neighborhood service street. San Francisco has 66 similar neighborhood commercial centers that are within walking distance of 5-7,000 people, precisely the population of downtown Dallas.
That nearly all of the office buildings around Thanksgiving Square depopulated is part of a broader issue that efforts in and around the site itself likely won't fix. Similarly, the success of Main Street and the critical mass, ie satiated demand, isn't enough to spill that far northward. And if it did, would it want to be in these spaces around TGiving Square? Is there an increment of opportunity above the initial and on-going capital costs?
There often isn't when there are structural, spatial, or locational deficiencies to the larger network. Herein, we sometimes presume that subsidy is necessary in these locations to "kick-start" further development. I consider these efforts like a form of urban defibrillation. You don't do it to an already alive area, where the market sees the opportunity and delivers sustainable, useful, desirable development. You also don't apply the defibrillator pads to long dead areas as it's just a waste of time.
Are the office towers around TGS long dead? Or just barely dead? The other question is, are the defibrillator pads better used on another "body" in another part of town. Or, are there even EMTs left to work on these parts of downtown when they're busy funding bridge redesigns and ferris wheel studies. All forms of decoration, attempting to wag the dog with the very tip of the tail. Integration ----> Accommodation -----> Decoration.
So absent the ability to amend the broader pathogenic network deficiencies of downtown AND absent the ability to amend anything within TGS, we're left with the very immediate context.
(The unused 'point' of TGS)
Ideas I've tossed out in the past, were to remove the leftover space at the point of the triangle that was seemingly forgotten in design and merely "shrubbed up." This area could be filled with decomposed granite and populated with movable cafe tables and chairs, similar to what have appeared in Pegasus Plaza thanks to Downtown Dallas, Inc., and usable by the public or the restaurants adjacent. There is only one restaurant currently open, Taco Borracho, which almost looks as if it is a food truck that grew up and filled in about 400 square feet (at most) of a vestibule. This place gets a lot of late night munchie crowd which could populate the 'point,' with a little lighting and some eyes on the street could be quite nice.
Another idea is to accept TGS' internalized nature, almost like a semi-private London garden courtyard, and line the walls with uses. Pop-up shops, food trucks, etc. However, this is what I call LESS BAD URBANISM, as in making things less bad through the application of stuff. It's also the kind of pseudo-urbanism that I abhor, treating symptoms rather than underlying pathologies.
Most "urban design" is of this mindset, operated under the belief that if you build it they will come. It is entirely supply side and often a shot in the dark whether it will succeed. Initial successes can often mislead until the novelty factor wears off. The burden of programming and populating becomes too difficult and unwieldy. The place is essentially on life support rather than a living, breathing organism. The reason is because accommodation was created (supply) without increased integration (demand).
The greatest return on investment comes through building proper network integration, not correcting flaws and distortions as they emerge, but creating a platform for maximizing the incalculable exponential synergistic potential. It's not about making things less bad, through top down efforts, but correcting the system's circuitry to allow bottom-up opportunity to survive and thrive.
So we need to increase local levels of integration. I've suggested that Pacific, the road along the south could be made two ways. However, there might not be the dimension to do this, particularly where the DART line converges with the road. Other options include streamlining the pedestrian routes to TGiving Square, particularly between the office buildings both north and south of the three-sided square. These areas are over-burdened with vertical circulation.
Vertical circulation is fine when the streets are so crowded that movement needs to spill upwards or downwards. Absent that population density, parallel planar circulation simply dilutes energy from the street. Furthermore, all of the infrastructure for bridges, tunnels, escalators, and elevators create visual barriers. People like to see where they're going and what is around the corner. Without that ability, people will choose other routes (if they're even there to make the choice in the first place -- again, see larger issues of spatial network integration).
Simply put, TGS is a tough nut to crack. That is, if we even want to crack it. I don't see the commercial opportunity nor will to do so because of the various systemic and physical barriers. Efforts may very well be better spent in other surrounding areas and hoping it will spill demand towards it.