I don't think it's so much older gamer vs young gamer that's the case here. I think it's more Casual Gamer vs Hardcore gamer.
Their was once an era when you called someone a "gamer", only one type of entity came to mind. He/she would spend countless hours trying to beat one game, be proud of how many games he's finished under his belt, brag on how skillful he is on all the games he's played, and see all his gaming accomplishments as something to be proud of.
Back then being a hardcore gamer wasn't a choice, IT WAS MANDATORY IF YOU WANTED TO GAME!!I remember playing Super Metroid where you have to jump and fly like a missile. I must have taken about 3 days to figure out how to do that but when I did MAN I felt I won the most L33T gamer award. Because the majority of games required you to figure it out!
Nowadays companies have SOO MANY GAMES coming out it's like "Okay, I'm stuck here so I'm going to play Angry Birds on my phone now"...
By saying that, now you have a choice between being a HARDCORE Gamer and being a Casual Gamer. A casual gamer would only pick up titles like CoD, Mobile phone games, sports games, and basically all shovelware that don't require much thought and reading, just DO, DO, AND DO. Unfortunately, this is making MILLIONS (if not billions) of dollars. Why? Because more people can "DO, DO, DO" than to "Think, analyse, Read, troubleshoot, solve". All games since the BEGINNING of gaming that has had that simple "DO, DO, DO" fomula (All the Mario Bros, Wii Sports, CoDs, the early Sonics, Halo, Donkey Kong) have sold more than their more difficult counterparts, regardless of "Old Gamer or Young Gamer". More people = More Buyers = More Money.
I started playing video games since the Golden SNES days. I played and finished all the classes (Super Mario World, A Link to the Past, Super Metroid, Super Mario RPG, Chrono Trigger, Donkey Kong Country 1 & 2). What I can say is that not ALL those games were hard (SMRPG, SMW, and DK1 certainly weren't). Super Metroid, Chrono Trigger, A Link to the Past sold 8.33 Million copies COMBINED while Donkey Kong Country sold over 9 MILLION copies! DKC2 is MUCH HARDER game than the Original, sold 5.15 copies with the sales down almost 40%! You see the trend? Easier games sell more than Hard games! Ergo, that's why they are more easier games for this generation, to please the masses = make more money
But then again, there are still very challenging games today. Take the "Tales" series or Xenoblade Chronicles. The length in those games plus the thinking you have to do to pass them is FAR more than what I had to deal with in my SNES days. Also there are some young gamers here that I've met that have also finished hard games, so again it shouldn't be OLD vs YOUNG at all. Rather, more of HARDCORE vs. CASUAL! 
