It's just that a screen with a $1000-$1500 projector will never have the same clarity and picture as a Plasma or LED TV. Also ... I watch TV shows, serieses, news, etc 70% of the time and movies about 30%. My current 50 inch TV is 8 years old and looks aweful on that wall, so I still need to invest in a newer TV. Hence, 75" cool looking TV sounds like a better option.
If I went with a screen, the biggest I can do there is about 92" because of narrow with and speakers on the sides.