The thing is, those OWL coaches have proven their ability in coaching, strategizing and arranging the team. Team members (highest rank players) agree with the coach, and improve their skills with the coach’s help. No plat or gold player can just knock on a professional team and ask to be a coach and instantly got accepted.
So, when a low rank rambles about some balance issue or POV, if high rank players don’t agree with them, that low rank is still a low rank, thus has no valuable inputs.