With regard to difficulty levels, has no-one here played BioShock 2 then? Feck! The difficulty curve is (like the original game) pretty (to use a pun) shocking. You are slaughtered every few minutes until you start getting tooled up. And even then, it's not easy. Still a fun game, but seriously flawed. You can rush through the game, not collecting ADAM or rescuing/harvesting the girls, but then it would be pretty dull.
But yes, I agree most big games are very easy nowadays and way too short in the challenge dept. I suspect this is actually deliberate as the game is done and dusted, so that -
a) The developers can then make a sequel (if successful)
b) The developers can make a new game (if not successful)
c) Short games mean punters buy more of them, more often
d) All of the above=more money for Mr Publisher (and keep Mr Developer in a job)