I know just how you feel. I played sports in school and my parents didn't come once. I was in a band and played 200 shows over the course of 3 years and they only came to one. I must admit, I am pretty bitter too.
It's one of my goals as a parent to be more supportive. I don't want to be one of those parents that comes to <b>everything</b> because I don't think that's what kids want, but I will come much more than my parents did.