I don't like my friends coming to see me perform stand-up comedy if they have to pay. Why should they spend money to see the over-produced version of a show they would get for free if they got me high at a party?
Then again, I can't begin to count what it has cost me to participate in my friend's weddings: air fair, costuming, gifts, nasty looks from elderly guests for not being family, nasty looks from the bride for being friends with the groom, hotel, parking, necessary after-party bar tab, etc. They might as well incur some of the debt as comedy shows and weddings are functionally identical: someone tells embarrassing stories about their childhood while everyone gets drunk and spends a lot of money. I paid to see their self-indulgent pageants, why should I feel guilty for charging my friends to see mine?
The only difference between a comedy show and a wedding is that the people who host a wedding go home happy.