I agree, Revolve needs a Midplane option.
There has been a lot of discussion about revolves in the forum, I'd be surprised if it was not already entered in as an enhancement request to Support a few versions back. Maybe it wasn't on the radar for things to "fix" or enhance. Now that there is the Feedback forum it should probably be entered there.
NateLiqGrav said:
Easiest way currently would be to revolve one side and then project to sketch with association the center again and then revolve the other side.