Even if true, the problem is those who don't but think they do.
I suspect you might also have parents who kinda like the idea that there child's behaviour can be explained by ADHD. My sister's kid often gets in trouble at school for example, and whenever this happens she will try to excuse it by saying she has ADHD. I'm not at all convinced given that imo it's far easier to explain the misbehaviour with bad parenting.
I don't think you understand. "Bad" behavior is one aspect of it but there are many others. Girls also have different symptoms (and are severely under diagnosed compared to boys). This is not a situation of excusing behavior you need to live and deal with a child every single day to understand.
I suspect you might also have parents who kinda like the idea that there child's behaviour can be explained by ADHD. My sister's kid often gets in trouble at school for example, and whenever this happens she will try to excuse it by saying she has ADHD. I'm not at all convinced given that imo it's far easier to explain the misbehaviour with bad parenting.