Yes that’s the socially acceptable thing to do. I’m a hardcore movie buff & if there’s a movie I want to see, I just SEE IT! It doesn’t matter if it’s with someone or alone, I go anyway. Unlike a rock concert, it’s a passive experience — you’re there to see the movie, not talk.
I always find that friends don’t always want to see the same movie I do or they may not be available at a time that’s convenient to me (like during the day for a matinee)
There are SO many things I choose to do on my own regardless of whether I have someone to go/do with or not. Why should someones lack of availability stop me from doing the things I want? :-)