Some very interesting points! I agree with most of them. However:
"- They are just as - if not more - expensive as a TV over time."
I paid about $600 for mine, brand new. And because it uses LED instead of a regular bulb it does not get hot like a traditional projector. Nor do I need to replace the bulb ($300) every 3000 hours or so. LED bulb (non-replaceable) on this projector is supposed to last approximately 20,000 hours. So about the same price as a basic TV.
"- They generally get duller or break more than a TV over time."
Mine still works perfectly after 4 years. No degraded picture or problems.
"- ... can be noisy, and sound often sucks compared to an equivalent TV (granted, some people have separate audio systems)."
The fan can be a little annoying, depending on where the device is situated. Sound goes to the stereo so audio isn't an issue.
"but for any serious setup, you wouldn't be able to move it around anyway."
The tripod stand is also quite portable. Seriously.
"I work in schools. We have DOZENS of projectors on site."
Projectors may not be the best solution in your case - schools. However, the article specifically mentioned "invading the living room". I normally use my projector in the living room.
"Projectors have a lot of problems that TV's don't have."
That's kind of a moot point. TV's have a lot of problems that projectors don't have.
The biggest reason that I went for a projector as opposed to a TV is a large, portable display. That, and there's nothing like helping friends and relatives move and lugging around some behemoth 50lb+ 52 inch TV, up and down stairs and trying not to scratch the walls or damage the TV. My projector is about as big and heavy as a home DSL router.
Projectors may not be for everyone but they are certainly worth looking into.