What are cinemas for?

Following their 25th anniversary, Back to the Future is being re-released in cinemas. Joyous times!!! Or is it? 

Fans across the country (including myself and many friends) are leaping at the chance to see this classic on the big screen. Many for the first time, considering our age. Yet I was shocked to find that some people didn't understand it. "I've got it on dvd, what's the point?!" I  was told.
   
?!?!??!?!

"THE BIG SCREEN! MARTY MCFLY! DELOREAN!"
Is what I should have scremed, but didn't. There was no consideration needed in my head as to whether or not I wanted to go and see it. Everything is better when it's bigger. [ No inuendo intended ; ) ]

But could my misguided friend have a point? Surely the whole reason you spend extortionate amounts on going to the cinema is the fact that you can't see it anywhere else. If said film were being played on BBC1 at the same time, I suspect very few people would actually pay to see it. So why should it be any different just because the film is old?

Should the cinema be left just for new releases? I leave the answer up to you.