I think it's just such a ridiculous concept that people aren't even bothering to entertain the idea.
You're suggesting demolishing a huge 8 floor building in Dallas which takes up approximately 80,000 feet of floor area and replacing it with a single statue of a man who was murdered 1000 miles away. I just don't see the link or the argument behind it. What are you hoping this will achieve?
I don't get the logic of destroying something so strongly linked with the assassination of JFK in order to replace it with a memorial of the George Floyd murder that happened well over half a decade century later. What's the link between the two? Just because JFK campaigned for civil rights?
Abraham Lincoln called for the abolishment of slavery so would you also suggest demolishing Ford Theatre and replacing that with a statue of George Floyd too?
Ridiculous concept. Erect a statue of George Floyd if you feel the need by all means, but to destroy such a significant part of American history to do so when there are millions of other locations to put it is just absurd.