I know Super Mario Bros. on NES (yes I used warps) as well as Mega Man 2. I never beat Mega Man (the first one), I could get all the bosses, but could never get through Willy's stage.
But to the point of your post, games are getting easier. Yes they are, and they have become so to be more accessible to more players... i.e. more mainstream, and this is a good thing. I know that I, as an older gamer, do enjoy the lower amount of frustration in games as I don't want to die 100 times to get to the end.
However, I think the industry has done a very smart thing to appease the hardcore gamers out there, Achievements/trophies. Not only can you say you did this awesome thing in a game, you now have an electronic stamp that you did it. So the game is beatable by a casual gamer and has a reward for the more serious gamer for doing something difficult. Mirror's Edge no gun achievment comes to mind as well as COD4's Achievement for beating levels on the hardest difficulty.