Like I said, "you could build a home theater with better sound." But most people haven't and won't. It requires time, technical expertise, and a lot of space. And with that you
only get a home theater. And you can't travel with it (I love the idea of using one on a plane).
But I'm sympathetic to the social-watching issue. I don't love the idea of watching movies in a headset while my wife sits next to me on the sofa doing something else (or even watching the same movie on a screen). But I also don't love the idea of buying two. (And that's without even thinking about larger families.)
I think home theater will be a big part of the appeal, but it won't succeed if replacing a home theater is the only thing it does well.