I don't think that anyone is suggesting that an immediate plan for the UA theatre has to be done. The facade of the building where the vestibule and lobby of the theatre is was going to be sealed up anyway... for future development. If the auditorium portion of the building is razed, it will just be another addition to the sea of parking beyond that. Is more parking really preferable to a sealed building that is mainly out of sight?
You are correct in that it will require someone with deep pockets to develop the theatre space [[plus there's always the revenue from naming rights). Right now there is no current need. But who knows if in a few years that might change. The theatre footprint would not be a hindrance to the redevelopment of the rest of the block as can be seen here...
https://www.google.com/maps/place/15...!4d-83.0530437
Unlike the Fox Theatre, which has every nook and cranny filled with ornate plaster, the UA has large portions filled with flat wall surfaces that were painted to look like medieval ashlar blocks of stone. Most of the ornate plasterwork survives, and although large portions of that have some damage, once a plaster mold is taken [[or gotten from its' near twin in LA), reuse of the plaster mold for repetitive surfaces is not as costly as one would think. And as for the resources for future restoration of the interior, there are several restoration companies nationwide [[such as Conrad Schmitt Studios) that specialize in this type of work.
If they powerwashed the auditorium exterior [[it already has a new roof), then it could be mothballed [[like so much of District Detroits surviving buildings are already). It doesn't look unsightly because both the Michigan Bldg. and the UA Building tower block most of the theatre portion anyway. And cleaned up, the exterior would look just like it did for over 50 years as a working theatre.
Once this space is gone... then there will never be another chance to "grow" the entertainment district. Once it turns into a parking lot... it will be that way for a very long time... :[[