Former NFL stadiums and what those properties look like now

I understand the rationale for demolishing stadiums which are immediately adjacent to the site of their replacement (i.e. the Georgia Dome), but what on earth is the rationale for razing places like Candlestick Park (even if the venue is triggering to Saints fans) and Texas Stadium? It seems kinda pointless to just demolish places that are so steeped in history only for the sites to be left vacant.

As an aside, I am always astounded by the amount of space occupied by parking lots at these stadiums as shown by the aerial shots. Places like the Superdome (which still has a decent allocation in and around the site) feel like the exception rather than the rule on that front.