But it doesn't matter whether they engineered it or not---if the fact of them buying up land, and thereby blighting it further, gives a boost to their eminent domain claim, then this creates a moral hazard and perverse incentive for future developers who want to eminent domain some land.

While I agree with the general thrust of this, I'm not entirely sure what they could have done better. Deliberately blighting an area to drive down prices and increase their chances is clearly not on, but when they've been clearly establishing a pattern of purchasing pockets of land with a long-term view to collecting them together for a grand scheme, should they really be required to let them out until they have the full compliment to avoid the appearance of blighting? This seems equally unreasonable; they are purchasing development plots as fast as they can and (within reason) should surely be allowed to treat them as empty development plots until commencement to maximise their chances of speedy success?

I think I agree with this; I just wanted to clarify.

Not thriving and blighted are very different. I live in the neighborhood and often go to that very gas station. The spot is far from blighted. Here is a street view of the station:

http://maps.google.com/maps?f=q&source=s_q&hl=en&...