So I'm very ignorant on projectors, TVs, etc, so I did a little digging and the Nebula does seem quite a set of compromises.
The usual problems with projectors is it is a compromise between brightness and fan noise. A TV / monitor spreads the by-product heat of making light over the whole surface of the display, which allows it to use passive cooling, while a projector makes all that light in one small area, and often is actively cooled with often quite a noise. This Nebula projector appears an active cooling version mentioning the fan so what is the noise from the fan? The manual talks about what it will do when overheating.
Also as far as I tell on the lumens side you can get a lot more brightness and a 55" TV with 8x the amount of pixels is still less cost than the projector.
I don't know how the Nebula compares to other projectors, in its peer group, but relative to just a big flat TV it does seem poor value.
This makes me think this is more about portability, than say in a bedroom. The use of a battery for example, so I'm thinking say business meetings, or say campiing where you hang a sheet off back of caravan or from tree branch. When you think in those terms of more outdoors (its not waterproof) situations then it falls more into a uniqueness category, which then may justify its price?