"Why play New Super Mario Bros. Wii when you can play Super Mario Bros. 3?"
Yeah, great logic! Similarly, why play Duke Nukem 3D when you have Wolfenstein and Doom? Why play Planescape Torment when you have the Fallout, Baldur's Gate, and Icewind Dale titles to wade through? Why play any game somewhat similar to any other older game, when those very older games still exist in some form or another? Everything should be 100% innovation, all the time, otherwise, what reason do you have to exist?
Sorry to inform you Yahtzee fanboys, but no, New Super Mario Bros. Wii is NOT the exact same game as Super Mario Bros. 3. It is similar in that it is a side-scrolling Mario-based platformer, but is essentially a completely new game. Why does it exist? Because the Mario games have a tendency to be, well, fun to play, and another game in this vein is more than welcome so as long as it's designed well and not just a straight port-over from other titles (like the GBA Mario games were, which I really have nothing against anyway), and from what I've heard, this one is one of the better titles in the series in quite a while. If you want to complain about this being billed as a full-priced "killer app" title instead of a budget release or WiiWare title, well, those complaints have a bit more merit I think. But, it appears none of you are even Mario fans in the first place, so why does it matter to you anyway? Actually, the one thing I legitimately WAS concerned about was that it was just a port of the DS title but with four-player co-op and some motion controls tacked on (wasn't that four-player Zelda game for the GBA and the GC the same deal?), but apparently all the levels and worlds are brand new, and is actually supposed to be far more challenging than the (relatively) easy DS title was.
I think I would respect Yahtzee more if he had no pretenses for being a "game critic" and that this series was intended solely for exaggerated comedic purposes, but from what I gather in interviews, that is unfortunately not the case. I suppose this is due in no small part to the sorry state of game journalism today, most of which is in major company pockets, but I don't think this is exactly the soundest alternative. I do wish him the best of luck in a career of game design though, not necessarily so I can say "oh yeah let's see you do better lol" but because, based on my experiences with the Chzo titles and 1213, he's a far more interesting and talented game designer than a critic, plus I get a sense of love and dedication to his game creations that I don't here, which seems most of the time cynically forced and abrasive designed just to shut up his constantly demanding fanbase and to get his next paycheck.