"I contend that aesthetics also includes the depth of the set which creates options for where the set is installed."
Sure, and in some rooms this is paramount. For ages, I argued that the attempt to make 7-inch-thick DLP TVs was pointless. No one would ever consider them flat panels or mount them on a wall in a house with a woman living there. Others saw 7 inch as "only twice as thick" and failed to notice the giant hunk of plastic below the screen. Well, the market vindicated my position.
I'm going to go further and say that I personally think the obsession with even thinner flat panel TVs is pretty silly. If it's on the wall, 3 inches is not much different from 1.5 inches. But, I'm not going to argue that all else being equal, you might as well make them all super thin. It allows even more installations to work
and generally is without a downside to those that would live happily with a 3-inch TV. Note, I said "all else being equal" which means price and picture quality. Whether a locally dimmed full-array backlit LCD can be made 1.5 inches thick is TBD
in large sizes.
You add some comments on speakers and the like and I'd say that the general lack of sound information on the rear channels (they are often just silent, sometimes they play crowd noise, etc.) makes them anything but a must have for most people. They tend to come to life very unnaturally on a lot of content, which makes them that much odder. Now, I have 5.1 and I like it, but I generally don't waste my time advocating that friends get it "if they're serious about sound". I advocate they get a receiver and real speakers and decide how many they can accommodate (up to a 7.1 system if the room allows).
As for the home projector market, it's generally measured from industry data that includes survey information. There are still people that buy business-class projectors for home use (they find them cheap, they don't know better, etc.) The market is really really small. I suspect even among the AVS user base, it's actually small. I haven't seen recent data, but there has not been evidence projector use is "catching on". It's generally limited to those with dedicated home theaters (a market that is flat-to-declining based on the current situation at CEDIA trade shows), specially crafted multi-purpose rooms, and a small segment of die-hard young males that just want the size, damn the issues or (sometimes) the quality.
It's foolish to dismiss the projector market, but it's equally foolish to suggest it's ever going to get much bigger.