I, myself, don't find anything wrong with sidescrollers, yet I find that it's more an Indie type of game style. I don't find that it should be acceptable in the next-gen consoles. Even with all the bloom that the PS3 adds to it.
Just because we now have the power to create 3D game environments, doesn't mean that 2D games are inherently outdated. Or that the only way to be innovative and cutting edge is to continue down the road of massive, photorealistic 3D environments. Something about the way you use the term "acceptable" implies that just because we CAN do certain things with our fancy new hardware, we MUST.
Not all games work well in 3 dimensions, what's the point of adding needless complexity to a tried and true game design? And why accuse a game style of being "Indie" or somehow less professional if they decide not to?
What I'm trying to say I guess is why try to fix something that isn't broken?