It's not hard to see why people are discouraged. Their record makes it really difficult to convince people "this time the Democrats are definitely the better choice" when Schumer and Pelosi committed so hard to preemptive compromise for so long.
It's not a good enough reason to sit out but we need something affirmative to offer to bring people back and I'm not sure what that is going to need to be. "Better than Trump" is such a low bar, nobody's impressed by it.