There's an argument to be made for professional presentations as well. I remember quite a few situations were something like this would be useful, and one time where everyone in the company I worked on got impressed with someone getting a small portable projector to make his presentation - is was very very dim even in a mostly dark room, and the image was so low-res there was hard-to-read text parts, but the concept hooked everyone.
Right now, unless you want a absurdly large image, there's no beating a large TV on price and image quality. But a large TV is stuck in place. There's a compromise to be made regarding both the price and the image quality here, sure, and it's a kind of niche product, but I wouldn't dismiss it completely. I can see a market for that, even at the current price.