I understand that someone would prefer a wired controller to swapping batteries every 50 hours or so, but i just don't think it is that big of a deal.
I too would find it impossible to live with a keyboard or mouse that required batteries, but that's because I end up using those two devices for more than eight hours a day. I don't play my 360 for more than three or four hours a day, and that too not every day. When I have friends over, then I end up using all four controllers, and they do run out of juice at annoying moments. But that's why I have a massive battery box in my TV trolley.
But while I can see the battery thing as a problem, I find the other two things to be non-issues. I've never had problems with the signal interference, nor have I ever misplaced a controller. Even if I had a wired controller, I'd still detach it and place it back in the trolley after I was done playing.
In the end, at the cost of being annoyed by the battery problems, I still prefer the convenience of being wireless.