It's not that the methods are bad or ineffective, it's that the advice is unsolicited and condescending. Do you offer to help everyone you meet with every one of their medical conditions? You meet somebody with a rash, and you say "just rub some vaseline with aloe on that, it'll go away." You don't know the cause of the rash, or if that will help, or if they tried it already. There's no "just" anything that makes ADHD go away.