The generational analogy seems perfectly apt, but that doesn't make out outlook worse or less sophisticated than the other.

Because the future is perceived as more advanced than the past, having built on the notions/achievements/etc., of the past. Arrow of time points in one direction. (At least for humans)

This is a very recent development, and it's still not universal. For the longest time, people believed that things were better in the past, that we are slowly moving away from a golden age, and that things are getting worse.

Some concrete examples are the biblical Garden of Eden/Armageddon; beliefs in Atlantis and other mystical places; the admiration for the Greek and Roman times, especially during the dark ages.