It's not like Republicans wouldn't have drawn a gerrymander if they had control. Maryland's map isn't nearly as ridiculous as the maps of Pennsylvania and Ohio.
It's exactly as ridiculous, and no one who voted for any of the three deserves reelection. -_-
The MD map is obviously a Democratic gerrymander and so is the IL map (which replaced a Republican gerrymander), and I don't like either of them for that reason. The only argument for these maps not being as bad as OH and PA's is that they more accurately reflect the statewide political lean. And that doesn't really hold up because its just another way of saying, "our gerrymanders are horrible, but it's okay because yours are worse, so its okay," and that's ridiculous. It is also absurd to say that gerrymandering in some state's is okay because (to paraphrase) "my party deserves revenge there."
That being said, it makes no sense for Democrats (or Republicans, for that matter) to stop gerrymandering unless the other party stops gerrymandering states in which it has the opportunity to gerrymander. Everyone wants fair redistricting when they have no say in it. But unconditional unilateral disarmament is silly. It is also naive to expect politicians not to try to help their party win when given the opportunity to do so. If people really want fair redistricting, then they'll support the establishment of a California-style redistricting commission in EVERY state.
If politicians are elected to represent their parties, your position makes sense. If politicians are elected to represent the folks in their districts and states, your position makes no sense. If gerrymandering is really bad for the folks in North Carolina and Maryland, then the representives of North Carolina oughten wait until the folks in Maryland are governed better before doing so themselves, and visa versa.