I can understand Sakurai's/Nintendo's reasons for roster parity, but I think it's rather silly. I mean, rationally, people should either want as much content as possible on the version they're going to play (or, given that the 3DS version already came out, be content with the content in that one), or accept the shortcomings of the 3DS version and not "resent" the inclusion of extra characters on the Wii U which doesn't have those shortcomings. It's pretty obvious that if at this point the Ice Climbers are added to the Wii U version, it's not because Nintendo wants to short-change 3DS owners or make them buy a Wii U for exclusive content, but because their inclusion is technically impossible on that platform.
That said, I'm more than happy with the roster as it is, so I don't feel too strongly about the issue, or the Ice Climbers in particular. Would I like more/exclusive characters on the Wii U version? Sure! Even if I wasn't going to buy it, I hope the game is as good as it can possibly be. It's not going to make me enjoy the 3DS version any less! But as the roster is right now, if it's the same on Wii U, I don't really mind. It's still a day 1 purchase for me.
That said, I'm more than happy with the roster as it is, so I don't feel too strongly about the issue, or the Ice Climbers in particular. Would I like more/exclusive characters on the Wii U version? Sure! Even if I wasn't going to buy it, I hope the game is as good as it can possibly be. It's not going to make me enjoy the 3DS version any less! But as the roster is right now, if it's the same on Wii U, I don't really mind. It's still a day 1 purchase for me.