Both, here are a couple of arguments:
- Nostalgia:
-- You started gaming as a child, simpler days, a part of you wants to go back to those less complicated times and, as such, also the things which remind you of that.
-- When you started gaming, everything was all new and shiny. Now that you're older - and your knowledge about the topic has increased - games simply don't hold that many secrets for you anymore.
-- When you're younger, things amaze you more easily.
- Why they were actually better:
-- You like JRPG's and Platformers and realize that these two genres have taken quite a beating during the 7th generation. In every other generation, they were plentiful and grand.
-- Too many shooters.
-- Too many people using the same engine and using the textures delivered with the engine instead of making textures themselves. As such, many games seem alike and have a bland look about them.
-- The uncanny valley effect, the more real people want to make polygonal stuff look, the more apparent the mistakes become. // You like games with a side-dish or surreality, but most games seem bent on delivering humans looking as real as possible.
-- Online gaming didn't exist, many games had offline co-op or versus modes instead - and playing with other people is still more fun when you're all in the same room instead of thousands of miles away over the internet. Also, you knew you'd be playing with your friends and not some annoying 12-year old who keeps saying he slept with your mom.
-- While some games are made a thousand times (WW II shooters), other games are made only once (ICO, Killer7, Rez, ...). So in that case, the best games were made in the past, because it is unique in it's kind.