We understand that you may have scheduling conflicts, but coming out and being a cool person can definitely make a big impact when we make the rank list. More than a few people have ended up matching based primarily on their performance the night before, and vice versa.
The only reason I'm going to miss any of these is because I have an interview the same day as the night-before event that is won't allow me to make it. With that said, don't you think that your chances of matching SOMEWHERE are better if you're able to make one more interview rather than skipping an interview to make a good impression at the social?