You mean that decade that brought back Care Bears, Strawberry Shortcake, Transformers, He-Man and the Masters of the Universe, Curious George, G.I. Joe, Fireman Sam, Sonic the Hedgehog, Duck Dodgers, Scooby-Doo, Tom and Jerry, Batman (twice), Spider-Man (twice), X-Men, Iron Man, Fantastic Four, Celebrity Deathmatch, and Teenage Mutant Ninja Turtles? Not to mention Doctor Who, Battlestar Galactica, Iron Chef, Bionic Woman, Knight Rider, 90210, and V in live action?
People have ideas. There are very creative people in the industry, but the executives want safe, touchstone brands that have stood the test of time. And as such, those creative folks often find themselves working on new versions of old favorites.
Oh, you're asking if anybody has an idea about why so many revivals are taking place now? Probably because people from my generation, who grew up watching those shows in the 1980s and early 1990s, are coming into their own and in a position where they could help refresh and reintroduce older, familiar brands for their employers.
That or they're just afraid to commit to new ideas. But what do I know?