[stoppingdown]

PS I'm not an expert of astro things, but I'm aware of the points you mentioned, as a close friend of mine explained them to me. But - for instance - some large, reflector based telescopes are capable to change the geometry of the reflector to correct for atmosphere blur. Sure, it's a multi million $ thing :-) but many things that we routinely do today were stuff for super-computers in the past. 

 

Also, I think that a 250MP thing it's for highly professional usage, and it would be coherent to hear that there is very expensive hw/sw in support. I can't image any other usage for being able to spot a person 20km far from the camera than security surveillance.