I get it. But lets face it even the brightest projectors within reasonable reach money wise are terrible for PQ in a semi bright room. The lamps have to be replaced constantly (I leave my displays on quite a bit) and the heat output is enough to replace a space heater. There are PLENTY of downsides with projectors. If you can't control your room lighting easily its just not practical. Now with a heavily light controlled room projectors can be amazing. But most people I know simply don't have a room they can dedicate to this purpose.
Plus a 4K projector? Starting at what? $7,000?
Projectors will always have the same pitfalls (bulb replacement could be eliminated with newer laser tech though and lessened with LED bulbs that last 100,000 hours versus 3000 at 75 percent brightness).
Of course this would just add to the cost, but it can do some pretty amazing things to mitigate the ambient light issue. Check out some of the videos: http://www.screeninnovations.com/materials/ambient-materials/black-diamond/