Everybody deserves to earn a living, this includes the mates.
I look at it as the same as going to a restaurant, if you can't or don't want to pay for the meal & a tip, stay the hell home & eat a box of mac & cheese. Or fish in the local creek, that doesn't cost very much.
I can't tell you how many charters I set up in the past, only to have my "buddies" argue & try to lowball the mate with a tip, I wound up digging into my own pocket to make up the difference. Same guys who drive a $40k pickup truck & spend $100/week on smokes & beer.