Everything you've suggested are things that most people who are aware that they have the disorder try or do already in order to manage it, I would be surprised if a lot of people found out they had ADHD and used their diagnosis as "an excuse for mediocrity or failure!"
If I were being uncharitable I'd say you were just using this comment as a way to dole out unasked for advice to either make yourself feel better or put down some straw-man you've made up. But since I'm not, I'll just leave it at you ain't said nothing slick to a can of oil.
