This exactly. You don't go out to eat at a fancy restaurant because the food is worth $40 a plate. You do it because of its value as a shared social experience with your SO, a date, your family or friends. Likewise, a movie on its own is not worth the $10-$15 a theater charges for a seat. Most of its value comes afterwards, from your ability to talk about it with other people who've seen it. Same goes for broadcast TV shows and live sporting events - the synchronized mass consumption is what makes them the topic of conversation around the water cooler the next day.
In that respect, an early rental would work for someone like me. My family room has a projector with 130" screen and a 7.1 speaker system, I could invite some friends over and we could watch a newly released movie together without the lines and screaming kids (or for the friends who have screaming kids, we can pause the movie until the kids stop screaming). But I suspect only a small minority of people have a setup like mine. If all you've got is a 42" TV with built-in speakers, what's the point? You spend all your alone time in your house already. If you're gonna hang out and do something together with your friends, you probably want to do it outside the house. Not to pay $25-$50 to watch a new release movie like it was a TV show.
I should add that I do use my home theater system in this manner. It's a lot of trouble to try to keep track of a herd of kids in a dark room, and embarrassing when one of them has a meltdown in public. So my friends and I do regularly get together with our kids for mass viewings of kids movies on my home theater. But here's the rub - the studios are putting out too many movies. We simply don't have the time to watch them all in this manner. So we're still trying to catch up on the better movies released a few months ago which are now on HBO or Netflix. There's little point watching a current new release for $25-$50 when we can watch as part of our subscription package a movie which was a new release a few months ago that we haven't yet had time to see. Saves us money, and helps us filter out the stinkers and bombs.