Especially since a movie is typically just a part of a day/night out.
Pretty much why they are not going to die out, at least not for a very very long time. Not everyone's a home body. There's a good portion of people out there who don't/can't entertain themselves while sitting at home all the time, even when it comes to watching movies. Like a lot of people here I'm sure, I am definitely not one of them. But there are people who are going to have the need to pack up their families/friends, get out of the house, and have something of a refreshing experience. Going to movie theaters seem to be one of the easiest ways to do this.
It's not quite like the case of arcade gaming being effectively supplanted by console gaming for a number of reasons (near universal appeal of film, extreme hype from the film industry, everyone is going for the same experience engrossing experience, tradition experienced by every living generation, etc)
If it ever becomes the general rule for pretty much all new releases to be released in both theaters and in the form of digital media, then we might have more of a discussion. I could see that happening, and it could do damage to theaters, especially if they don't charge an exorbitant rate for the home version new releases.
I'm all for ripping off venues that rip you off to begin with.
I miss drive-ins, but there really is no place for them anymore, sadly.
The best practical advantage about drive ins that I've found is that you can actually get away with bringing a baby to them.
Also, I dare you to have seats as comfortable in your living room. The theatre's seats are AWESOMELY comfortable, which makes me wonder why similar seats are not available in more places.
A lot of people from North America reading this are going to laugh. Many middle class living rooms here have a large tv with spacious and comfortable sofas. Like Fast said, most cinema seats here aren't exaclty amazing.