So, to respond to the notion that all games should be multiplatform, I would say that I very strongly disagree. Let me explain why.
Outside of smaller concerns like porting costs (porting costs increase overall cost, which generally decreases risk taking), the primary reason to desire exclusives is interface. As a simple example, imagine if all RTS were on all platforms, and were forced to simultaneously be playable using a KB/M and also a standard controller. Imagine The original Bayonetta requiring compatibility with both the standard gamepad but also KB/M and Wii mote. Imagine if Street Fighter needed to be tuned not just for the Arcade Stick, but also Wii Mote; or if MOBAs like DotA 2 had to be reasonably playable with the Dual Shock.
RTS are fundamentally changed when they are forced to be playable with a gamepad; I wouldn't say they are bad games, but certainly very different. And that is the real problem with this list; it forces homogenization of design. RTS games designed around the game pad are different than those designed around KB/M; fighters designed around Wii Mote play very differently than those designed around game pad, and so forth.
Forcing all these games and genres to be multiplatform on all platforms would force all games to have similar design because none can be tailor made to their specific controller. That is the primary problem with absolute multiplatform development.
I see what you're saying, but I'm not sure how true this is.
RTSes are practically unplayable on a gamepad, and even the games designed specifically to make it happen (Halo Wars) haven't gone well. In that regard, it seems more likely that this will result in consoles adapting a control scheme more befitting the genre, such as how the Wii has become mostly reliant on the classic/GC controller (and Madcatz's TvC stick) to support a fighting game community. Yes, GG:AC had motion controls, but nobody used them because they were ass backwards and all of the involved parties knew it. A similar example would be the release of UT3 on the PS3; the game is basically impossible to play properly with a gamepad, so the game shipped with KB/M support.
As it is, a lot of design effort is put towards homogenizing input and UI compatibility towards the gamepad (Call of Duty, Skyrim, Dragon Age; there are probably others) even when the gamepad is not the traditional or most effective control scheme, and the KB/M control scheme remains largely dominant on that platform. I don't see this as a major concern right now because the players of the game know how best to interface with them, and unless the developers start actively preventing people from using less efficient or more efficient but less popular control schemes (gamepads for FPSes, arcade sticks for fighting games) I don't see it as a sufficient enough concern to discourage mutliplatform releases.
Having said that, as control schemes continue to become more abstract, I can see this line of thinking becoming more relevant. I wouldn't say that many titles on the DS that I've played have yet reached the threshold (TWEWY comes to mind fist for me, and even that is being ported; Ouendan/EBA comes close, but that exists on the PC and it's still pretty fun) but the games on that platform in particular are getting closer as designers get more and more creative. But for home consoles -- where the option exists to change the input interface entirely on the fly -- I don't see this as a concern.
In terms of Bayonetta, unless they do something radical -- like making the game controlled entirely by the Wii Fit board (please don't do something radical to Bayonetta) -- I can't see how this concern is relevant to Bayonetta, except that if you asked me to pick a current generation console that has a default control scheme least adapted to playing Bayonetta (between the X360, Wii, PS3, and the PC), I would be pretty confident in saying the Wiimote/nanchuck.* In parlance with my argument, ever since this game was announced I've just been assuming that we'd all be playing it with the classic controller.
*For others it may be a tossup between the Wiimote and KB/M. But I think we can all agree that the standard gamepad did a pretty good job of controlling Bayonetta.