There was an article in Spielbox not too long ago that sort of discussed this a bit. Their general idea was that gaming changed around that time with the advent of several relatively new developments–the co-op game (there had been co-ops before, but not as refined and adult-oriented), the deck-builder (spearheaded by Dominion), and the traitor mechanic (all vs. a hidden 1).
Like you, I don’t enjoy those older games as much–I will periodically play one, but Settlers of Catan is the only one from the 90s that I will still bring to the table with any frequency. I know that game is frowned on by a lot of gamers now because it’s become so mainstream and seems easy to master, but I still feel that, at its core, there’s a lot to the game and that the variable board remains a huge attribute. I never get tired of it.