The reason why the Wii U screen should have multi-touch is because the hardware should provide as many options for developers as it can. The Wii was clearly designed for Nintendo's own studios and as a result most third-parties didn't want to create games for it because it didn't offer them what they wanted. There may not be very many uses in games for multi-touch, but I personally believe that motion control is pretty limited in what games it works well in and Nintendo designed a whole system around that. Besides, I don't think anyone who visits this site is a game designer, so just because we can't think of many uses for multi-touch doesn't mean that game designers can't. All I know is that if I came up with a game concept that'd work best with a multi-touch screen, and I didn't have it available to me, I wouldn't be happy. As the old saying goes, it's better to have it and not need it than need it and not have it.
That's just my view, of course.
As for Resident Evil, I don't think the first three games were universally praised at the time of their release. They've always had people criticizing the mechanics, so that's nothing new. They aren't like most of the good NES games which were praised around release but are now considered to be aged and mostly unplayable by anyone who didn't grow up with one. Even if they were though, I don't have a problem in saying that a game is no longer good, because sometimes modern gaming makes the flaws and limitations of older hardware that much more noticeable, and not everything is still worth playing today.