You hit the nail on the head! "Side-scrollers" (or even "2D games " for that matter) aren't going anywhere. They capture a very pure/simplistic form of gaming that's difficult to come by anywhere else. You can't underestimate the power of "pick up and play" that these games provide. -That being said, I believe that any videogame genre (if done right) can be successful. As long as there's VARIETY in the gaming market then the industry will thrive for sure.