It's one thing that you can't call out Taash's immaturity, but it's another thing that the game tries to reinforce this as a good thing.
The game goes way out of its way to villainize Taash's mother as this uncaring, unfeeling mother who doesn't give a shit about her kid and doesn't understand her. But that's just it: she didn't raise her, and openly admitted to it. My Dragon Age lore is a bit rusty, but if I recall correctly, Qunari children are raised by the priestesses until they reach an age where the three governing bodies of the Qunari can place them in a suitable role and integrate them into society. Taash's mother was a researcher, so clearly she didn't raise her. Listening to Taash try to blame her mother for something she already knows is one of the most repetitive plot points in that game, and it removes any and all tension from the scenes the minute it's brought up.
As a researcher, Taash's mother would fall under what her people would call "The Mind of the Qunari," so their super into obtaining knowledge, creating things, finding things out that would better help their people, and researching artifacts. When Taash's mom starts asking questions about Taash's gender, she's quite literally doing her job as a researcher: asking questions to better understand something she doesn't know. And instead of building on that positive quality, the game reinforces it as a negative aspect of her character, just to make Taash look better in comparison.
It's fucking mind-boggling that there's only one person in the game that acts like a Qunari in Veilguard, and that's the character the game wants you to hate. If this is the state of the writing in Bioware, then Mass Effect 4 is fucking cooked. Representation was already fine in the Dragon Age games and didn't need to change. There's a reason why games like Baldur's Gate 3 and Cyberpunk 2077 handlethe gender shit better, because the story and the characterization and lore doesn't have to take a backseat to it. And that's basic writing 101.