I don't see how a fixed camera limits immersion.

The most immersive MMO I've ever played, as in got completely taken in to where I could truly "tune out" of my immediate physical surroundings, was Ultima Online back in '97/'98. It was all 2D, top down view, no zoom, no camera control. Just a bunch of low-res sprites running around a flat, 2D world. At it was freakin' glorious!

I've still yet to find an online game that has provided as much of a "get completely lost in the game" level of immersion as Ultima Online did. None of these newfangled 3D games with fully controllable cameras come anywhere close. But then, I grew up with Atari and NES, so I suppose the younger generation growing up on today's technology are so used to controlling the camera that once they can't do it, it breaks their immersion. It's the exact opposite for me. Once 3D games started coming out, I found that having to move the camera around, separate from my character's own movements, was immersion breaking to me. I'm used to it now, of course, but I do still appreciate (and prefer, depending on the genre) fixed camera games these days.