I think Ciaran summed it up best. I certainly look upon the 90s with a lot of nostalgia, but I also grew up in the 90's, so I have childish ignorance on top of general optimism. I really remember everyone being both excited for and worried about the turn of the millennium because the year 2000 was "the future" while also being the year the feared Y2K bug was going to hit.
I also actually remember being proud to be an US citizen then. Might be a spillover from the Regan years combined with the fall of the Soviet Union, but it really did seem like the US was the greatest country on Earth. That delusion continued into the 2000's, but no farther.