While I'd be the first to talk smack on my fellow Diamonds, 99% of the time I'm not genuine.
Golds and Plats lack many things Diamonds simply know as a basic. Rotations, champion limits, map awareness, mental. A Diamond player on their main and role, will easily stomp 90% of all Plat2 and below. There is a gap between P1-D4 players that is muddied, but ultimately if you are in that range that's who I'm talking about.
The problem with Diamond is this...
Boosted Diamonds sully Diamond. Content players ruin games, Trolls are just better at trolling then all other elos below. When you have a "bad" player, it more prevalent because the other 5 players are Diamonds not Gold. Meaning their skill and how to abuse that player makes it harder for you to carry or make up for that players slack.
Theses are the factors that make all elos mesh. If you think it goes away the higher elo you get, you're sadly mistaken it get's worse.
If all players where always playing 100% you would never say that, but they don't because this community is really really toxic in all elos.