You're not cutting anything off, you have a wider field of view. Since almost all action in movies or games happen in the 7 feet immidiately above ground all the way to the horizon, there is very little point spending screen real estate above and below what is needed to display that.
If you fill your vision horizontally with a 16:9 monitor you're missing the top and bottom. If you also fill it vertically you wasting pixels off the side. But no-one does this, so you just end up with the top and bottom cut off.
In games, and particularly first person games you're frequently looking up and down. Portal wouldn't work without it. More vertical visibility can be a great plus. 16:9 is very restrictive for first person games. I'm very much looking forward to the Rift, assuming they don't letterbox the thing ...
Why would FOV be the same as 4:3? you have a wider screen and a wider field of view.
Some games restrict FOV for gameplay reasons. The can work for or against 4:3 monitors. Bioshock made some good compromises with its restrictions. In Team Fortress 2 you can set the same FOV for 4:3 as for 16:9. The game is better if you do, as it's a game where you have to look up and down. Left For Dead on the other hand make 4:3 use a horribly narrow FOV that practically breaks the game.
Nobody games in portrait mode. Nobody uses surround gaming by stacking monitors on top of each other. Why ? Because all you get is sky, ceilings and floors.
Millions of people used to game in portrait actually! It was incredibly common in the arcades. My monitor can pivot into portrait, and I've used it with my Dreamcast which has a good number of TATE mode games.
Reminds me, I need to get Ikaruga on Steam on flip my monitor on its side ... stacked monitors for vertical scrollers would be fucking awesome!
But regardless, just because protrait isn't ideal for most games, it doesn't mean that 4:3 should be judged the same as 3:4. Your eyes, after all are kinda 4:3 ish, and it must have had its uses over the millennia.
In 16:9
You don't think the latter framing conveys more presence and intimacy ?
I'd probably think so in a movie, as like most other folks I've been conditioned to know that's what the director would want me to associate.
Not so in a game, particularly where I'm in control of the camera. More like with real life, I wouldn't need or even appreciate that kind of framing. It would be an intrusion. I want to see as much as possible and read cues more naturally.