Contractor here. Well you are not obligated to accept the contract if the rate is too low. These Lyft / Uber drivers do the same thing, the rate offered by Lyft/Uber for a ride is too low so they decline and only accept if they get their preferred rate. The same as software engineer contractor does, I don't accept every contract opportunity when I am in between contracts.
In Uber Pool / Lyft Line, drivers are not allowed to refuse extra riders. If they accept one of these jobs they are locked in to whatever jobs Uber/Lyft throws at them afterwards unless they want to end their shift.
That's why they log out of the app / turn off their phones instead of canceling rides. So they are just not available in the driver supply and then when they log back in they get surge price.
It seems to me that Uber's counter argument would be that they aren't obligated to offer a contract to all contractors equally. They would further argue that Uber's product is availability of drivers vs the rides themselves (remember they are only the middle men) and that they provide preference (in a binary manner) to contractors who allow them to provide consistent availability.
