this is a hacker crowd -- I imagine most people here have a ton of content already on a computer, which using a projector makes it much easier to watch.
1. agreed on dark room.
2. if the projector is mounted high (as it should be) this is not an issue
3.I was in military barracks half the size of a normal bed room and my projector still had a very tight 4-5 foot screen on a bare wall -- oh and it was $600 OTB.
1. A dark room
2. Nobody getting in between the projector and the surface it is displaying on
3. Extra space
Don't get me wrong, projectors are cool, but there is a reason they aren't as popular as regular TVs.