Contracts can be pretty arbitrary.
"Independent contractor -- except can't turn down a ride."
If a contractor had a contract to accept or decline every jira ticket (although I don’t see anyone ever forming that contract), if they declines too many tickets they would no longer have the option to pick.
Most customers will search for a range of rating + price - so the market can regulate itself. I mean we accept amazon displaying user ratings - so I don't know why this won't work.