IR aiming is not a mouse-like input. It's relative, not absolute. Turning and turn speed is determined by the location of your cursor on the screen - that's not how mouselook works.
Gyro, on the other hand, is actually mouse-like. It's absolute. That's why I'm such a huge advocate for it. It's reliable and precise, unlike IR aiming.
You're talking about application, not tech. Unless you mouse is calibrated to move around a mouse pad that is exactly the same size as your computer screen, it is also relative. IR and mouse are much more similar than gyro, this is self-evident with a 'point and click' or lightgun game. You can also set IR aiming to work exactly like standard mouse quake setup, with no or a very small dead zone. So you turn instantly upon any move.
You're just pointing a Wii Remote at a screen instead of your mouse's sensor at a table/pad.
Also, you don't necessarily 'point at the screen' for IR either, it remains just as relative and configurable as a mouse for this reason - you are actually just pointing at two IR reference points, not the screen. As such it can be calibrated so that very small movements of the pointer mean big movements on screen, just like a mouse. The only difference is you can also change pointer sensitivity by changing distance from the screen/bar as well.
Gyro is really just a combination of (infinitely?) more accurate non-pivoted stick for looking up/down. The simplest example of this is in Mario Galaxy with the upright Wii Remote controlling tilt on a ball.
I agree gyro is better overall for shooters these days. But I didn't say IR was, I said it had specific applications that were, and that in my opinion both were superior to sticks.
