See, my problem with this statement is that from what I've read, Steph was quite competent, up until the Batclan started saying, "No, you're not good enough, go home," and only after that did Steph start being written down in competence, as if the writers can make Batman, Tim, and Babs look less like incredible dicks by retroactively making them right.
When Steph started off, she was doing pretty good. She was a rookie making rookie mistakes, but she was smart, tough, and really interested in learning things from anyone who would teach her. She had guts, she had smarts, she had potential. Even Batman thought so.
Since then, it's become Official Batclan Line of Argument that she's not good enough, period. Not that she's working on bits of training scrounged from whoever would teach her for a few weeks before declaring that she should stay in the kitchen supporting cast, not that she's scrambling together gear out of babysitting money, not that she's gotten used to ignoring authority because the authority she knew all her life was the Cluemaster, but that she's just. Not. Good. Enough.
And that's bullshit.
First of all, it's contrary to the whole mythos of Batman, the superhero who most of any in the DCU made himself into a first-tier hero with nothing but the will to see it done. Second of all, y halo thar condescending paternalistic don't-worry-your-pretty-little-head patronizing--Steph has too much self-respect to listen to the kind of crap men (and Babs) in her life keep throwing at her. Third of all, it's, beyond all doubt, the worst teaching method in the history of ever. Here's what it sounds like to me:
"Hey, Batman/Robin/Oracle, I want to be a mathematician like you, but I'm having trouble with some stuff. Can you help me out?" "Let me see...passable, passable, passable...what's this? You've done these integration problems wrong! You'll never be a mathematician! Go home, little girl!"
Besides, the Batclan has repeatedly declared that they don't care enough about Steph to consider her one of them. If they want to "police their own", fine, but Cass is the only person who has shown any sign of thinking about Steph that way these days. So until and unless she shows back up (and man, I would kill for a Batgirl&Spoiler ongoing), there's no one with a right to tell Steph a damn thing.