Puttting in Online Multiplayer doesn't hurt Mario in the slightest, but satisfies all the people that demand playing with random people online. You still have your precious single player and local player. Its downright mean as a gamer for you to want Nintendo exclude such a critical feature in today's pace of gaming from other gamers, just because it doesn't conform to your tastes. I didn't want Nintendo to put in "instructional videos" to teach n00bs how to play their games and solve puzzles, but Nintendo did it anyways, and because I don't use them, they never effect me. I didn't want Nintendo to put in Easy modes for Fire Emblem and Donkey Kong, but they did it anyways, and it didn't effect me when played the game on normal.
I mean its twenty-fucking-thirteen. Rest of the consoles graduated to Internet nearly an entire decade ago, and just imagine if the Nintendo games that were online now, had their Internet taken away, just because you thought "oh well its meant to be played with friends only" If that were true, then we wouldn't see so many damn threads of strangers trading friend codes. I've traded 10 or so Animal Crossing Friendcodes with complete strangers and dabbled around in their villages for awhile. It was more fun than the game could possibly offer by itself, but do you think I'm going to care about these strangers or play with them again 10 days from now? Like fucking hell... All I wanted was someone to experience multiplayer with, something I would NEVER EVER EVER experience as local play in the real world. I'm not in highschool anymore. the only time I see someone with a 3DS, or a NDS in their hands, are atleast 15-20 years younger than me, and my 3DS is at home anyways. And the entire life of Wii since 2006, if I didn't have Internet Multiplayer, then I didn't get to enjoy multiplayer's fun, period.
And finally, just imagine Mario Kart, Animal Crossing, Smash Bros without Internet... why would you wish that sort of injustice on Mario? I really could go on and on about this issue, but I gotta be at work in 20 minutes :\
You think playing with strangers makes the game harder due to a lack of communication? Fuck... I welcome that, with as easy as Mario games are. People can enjoy playing cooperatively, competitively, or both.