IMO, and sorry to be late to the game, but the Home Theater should be Home Entertainment and fully encompass everything from Audiophile to Gaming to Smart Homes.
But to the last point, smart homes, that would require some standardization. Which doesn't seem to ever happen.
Likewise, I read someone in this thread touting DA Music. I may be showing my age, but many standards over the years was touted as being the next best thing for music and they all faded and we still have stereo.
BTW, recently I read that a lot of gaming stores are dying. That surprised me because it didn't sound like they just meant B&M.