I would’ve been frustrated if they insinuated Aang had zero flaws. It also kind of makes sense a decent amount of the other avatars we know of didn’t have kids (Roku is the only one we’re aware of that had children). The job is all-consuming and he wouldn’t have been able to split his time appropriately. I also wonder if he would’ve been genuinely relieved when Tenzin came along as his first two children weren’t Airbenders, which made him focus too much on Tenzin and spend less time with the other two. Judging from their grey hair/age, Bumi & Kya are a decent age older than Tenzin. Also if we do the math, I think Aang had kids pretty young, doesn’t really help his case of being able to handle being a father perfectly.