We were on track for a BTTF2 future, with glitzy tech, flying cars, and fusion as a main power source.

Dude what? This both isn't true and makes no sense in the context of the conversation, lol.

But I'll bite: in what ways we on the path to developing flying cars before 9/11? Who was developing them? When were they going to be implemented? How did the events of 9/11 change any of this?

What examples of glitzy tech were we supposed to have? Do we not have certain examples of such tech right now (e.g. smartphones, smart appliances)? How did 9/11 derail all of Western technological research?

Fusion is still being actively researched so I'm not sure why you mention it.

For the kids at home who don't remember 9/11, it really just shifted the American psyche from being optimistic to bring cynical and paranoid. The world just feels less safe now.