Babs' was out of the suit for almost a decade, and Tim was a fresh face.
I think you have things backwards. They weren't popular because they were the first mantle holders to have their own series, they were popular enough to get their own series. Being under the Bat department certainly helped, to be fair.
Cass wasn't cancelled because she was unpopular, her series outsold several OYL series that were brought back, including Catwoman. She was kept suppressed for a decade by the powers that be.
Any and all fans can see the puppet strings clear as day in this information age, and we know what they mean.