Imo, both positions are extreme. I mean to play devil's advocate here. As I think you are doing too. However, it is not "unnecessarily" pessimistic. There are

Imo, both positions are extreme. I mean to play devil's advocate here. As I think you are doing too. However, it is not "unnecessarily" pessimistic. There are actual fiction books, congressional hearings, military strategies in motion that play out such outcomes. The US has a space force command. And missiles to space have been sent to knock out targets. Calling it a fallout, implies when all things fail and hell breaks loose.