A lot of people are turning around and selling these on ebay or some shit, or would be if they were free. Also the studios probably want them charging for these because it means they can pay them less and expect them to make their own money at the cons. The pay especially for a shithole, rinky dink operation like Funimation, is shitty as VA pay generally goes, even for the generally low paying world of anime dubbing.
So they're all competing for a piece of a finite pie and that makes a good explanation for yet another motivation for knocking off a guy who they felt was taking a disproportionate slice of the pie.
If I were a fan of some particular thing and there was a middle man, especially a real piece of shit operation like Funimation involved, I wouldn't feel terribly guilty pirating the product and making it up by paying one of the guys who made it directly.