... or because they thought wings would be pretty cool looking?
Many changes DO get fixed in a population because they are 'cool looking' ... to prospective mates. Sexual selection means that 'cool looking' gives greater reproductive success, because without mating reproduction is zero. And it's reproductive success, not 'survival' per se, which is the key.
I thought you addressed THAT part of it adequately, that the variation comes without regard to need (or looks).
Just pointing out that 'cool looking' has more of a place in evolution than the seemingly dismissive tone suggests, not that 'trying' to get a cool look is the way it happens.