Platinum is still garbage

Why are people in platinum still garbage, isn't it the top 10%? Im not just saying that all my teammates are bad and i can't clime, but im saying most are bad because i have factual evidence of their play style, calls, team fights, etc. I can see what they are doing wrong and they will not accept it, or the builds i tell them. They just don't listen or do anything, or communicate at all. And finally most of these people get really lucky to get to plat, or is juts pure elo boosted garbage, for example i play with diamonds all the time and yet they are the most likely to feed. and if anyone wants to respond that im garbage, lets play a game together and tell me what im doing wrong, explain to me, dont just say that im garbage