I work at the cinema, and don't look down on people who are blatantly going in alone to watch a film. However, I pretty much get free films but won't watch them alone (save for sitting for half an hour in a screen on my break or something). It's not because I feel people will look down on me, it's just that I feel lonely watching a film by myself and would much prefer at least one person with me. So I say if you're okay with watching films by yourself, then do it. If you're not, don't.
On a strange side-note, im mostly fine with watching DVDs at home by myself. Double standards really.