Nah, they were just that good! I'd rather sit and play an 80s/90s Nintendo title now, than 90% of what is released now.

Rarely have I gone back to an old Nintendo classic game and said, "Man this did not age well." So, I think they were rated appropriately. The newer ones on the other hand....

Wow this is totally bullshit people saying "less good games competing with mario,zelda,etc. is why nintendo games seemed so good blah blah" i would love to see the people making these games nowadays do it without all the quote unquote "playerism" they have done to nintendo's games since the beginning because everybody "borrows" each others ideas over the years with a few tweaks if even that (dantes inferno anyone? complete ripoff of God of war) nintendo didnt have anything to influence them all their ideas were original. The technology just wasnt worth a shit before the NES, pacman was like the pinnacle console achievement. So nowadays the critics are harder on games but rightfully so. They have so much help having all the games of the past to help get a foundation on their own game from. Its makes its so much easier having something to compare your game too, which is why the wii u is having a hard time keeping 3rd party companies developing on their console because the internals is different from what their used to making games on, nothing to compare it to. Games were great back then, its easy to look back now and say blah blah but lets look back on the ps4 in 30 years and see what we have to say about it. you cant say it was easier back then because technology was new to them, and if it was so easy then why didn't every company have a million selling game then?

If you're 'rating' games based on much else besides fun, you're doing it wrong.

All games are rated based against their competition. So yes the competition is higher thus it takes more now. At the same time games now have the advantage of using elements that did or did not work in past games(for instance camera control in 3d games has been a work in progress for about 20 years now).

No. They're rated highly because they invented entire genres, that's why.