An exchange from the 3D Land v. NSMB 2 thread a few days ago that's relevant to what's going on in here I think. It's pretty obvious to me the strengths of NSMB 2 (e.g. the excellent level design and Coin Rush mode) get unfairly dismissed just because it shares the same aesthetic style as prior NSMB games. Its biggest sin for many people is simply being an NSMB game.
To be honest, this isn't even a NSMB2 thing - many people merely used NSMB2s 'recycled' graphics as the clinching final proof that New Super Mario Bros was crappy and Nintendo hates us for not making every single Mario-branded game like Galaxy.
Some who don't like it stated that way may claim I'm oversimplifying it. But really? I was there for NSMB Wii. There was a shitstorm of hate for NSMB Wii before it launched, with plenty of plenty (on GAF, off GAF) laughing at its "cheap flash graphics", and the fact that it looks so dull, old fashioned, and boring. Some people were calling it shit because Splosion Man was "much better and only ten bucks".
This was before the game actually came out and sold tens of millions of copies, ah-heh. After THAT point I seem to recall many of the popular narratives shifted to how it was "Just a game for casuals" to explain why it was popular. That narrative re-emerged when Nintendo revealed NSMB U at E3 - how we deserved a "real" or hardcore (?) Mario instead of more generic casual junk. Because 2D Mario is casual now, at least when it has graphics we don't like. The hate and rationalization directed at the NSMB franchise is so cartoonish, it's difficult to not frame it in a cartoonish manner.*
Anyway, I won't derail the thread further with the usual case of
The People Vs New Super Mario Bros. I'm sure the NSMB U launch thread will suffice for that or something
* Please note, pointing out that gesticulations of disgust at a game are overblown is not the same as saying people can't
dislike it. When you present your dislike in a silly manner, you may be called silly.