and yet clearly there are more people who feel otherwise, hence it's sales. So it is really more of a personal problem. I mean, bad example, but i know more then one gambling addict. It's still a personal problem each person grips with.
Heck, look at all the internet love with the bronies. As far as I can tell it's unironic, actually watch and enjoy said show like mostly.
Mario's childishness is really part of it's charm at this point. Bright colors, ineffectual funny villians, the atmosphere more or less replaces what a deeper story normally would.
I don't see any difference between say Mario or Phineas and Ferb for example. Tons of adults enjoy that show. More then kids I think.
Mario IS the kind of game adults can, and do enjoy. Just not one you personally enjoy.
Now compare that with Disney movies, which almost all adults will admit are timeless classics (the main ones). It paints a rather different picture I would say. Phineas and Ferb is not in the same league.