What? I think you've been going to the wrong gigs. A lot of the casual fans or people just passing at festivals are crap to watch decent acts with. I find most acts tend to be much better at their own gigs. Sound, atmosphere, intimacy. There are some exceptions when I thought a festival show and crowd would be hard to beat. Glastonbury - Rolling Stones and Leeds - Rage Against the Machine stand out for me, but then when you see the likes of Foals at a 220 capacity venue it's a feral atmosphere, you just don't get that at a festival.
Saying that festivals can be much better value if you like the headliners and some of the undercard