Actually, most (but not all) of the people giving away copyright are the hangers on.
The ones I have met are just trying it out for the fun of it, and the clients they have aren't really into elaborate weddings. It's weekend warrior or Aunt Mabel. They get what they pay for, but as they don't want much they don't pay much.
In Britain, judging by my cousins, almost all wedding photography is done by hordes of relatives with P&S's.