The same trite rehashes keep getting made because they keep selling loads of copies. I look at this the same way I look at most pop music, talent is optional because if you shill a product enough, the market will believe it's "good."
On the other hand, I have no problem with games including plot as a selling point. I enjoyed Mass Effect despite the clunky interface because the character interaction and worldbuilding was above average, in my opinion. I enjoyed ME2 in part because of that, but I also felt the gameplay was more streamlined but still presented plenty of replayability due to party composition and henchmen skills. I guess my response would be, if you don't like roleplaying elements, why would you spend time ranting about an RPG? I don't ragequit Ocarina of Time because it isn't Doom.
On a different topic, I don't understand the short attention spans of most players. According to steam's achievement tracker for Fallout New Vegas, 30% of the people who bought it never reached level 10. That's a pretty hefty investment to just put down and walk away from, from my perspective. I feel compelled to at least finish once if I've paid that much money for something. Honestly, it seems to reward developers for skimping on the endgame (like Xen, apparently. I'm still working through Half-Life). I think the only game I've purchased in relatively recent memory that I couldn't finish once was Shadow of the Colossus, which I found mind-numbingly boring.
Fakedit: Wow, septuple ninja'd.
I wouldn't take the "rawr mindless FPS" generic hate too seriously, we are on forums for a company that does roguelikes after all. I've never played either L4D but they looked fun. My main issue with those kinds of games is I don't have access to a group of friends to play with, and loudmouth kiddies make me want to drill a hole in my head.