Its all about supply and demand.

You can find a bunch of guys that would fuck a hot girl on camera for free (Midnight Prowl, etc..) And with all of the wood stiffening drugs, there are more and more guys willing to work for nothing, bringing down the demand and the need to pay anything more than bare minimum.

Just think of how much a mexican from the home depot parking lot would do it for?

Kidding, but it further illustrates my point about more workers for less money, and supply and demand. "If you don't want to do it for that price, I will have no problem finding someone else who will"

And POV directors have their cake and eat it too, not having to pay an actor and getting laid.