Every bottom division is like that, with exception to Iron (Iron is "wtf are we doing?" as being clueless, not as flame) But I'd have to say that a lot of higher elo players (on youtube) seem to agree that plat is probably the most toxic elo in the whole game, even more than silver.
The way I understand it, Silver is the level of "I'm not bad anymore! But apparently I lost the coinflip, and my entire team still is bad, so feed me, mr. jungler!" (To be fair, this is extremely accurate, and especially this season where matchmaking is quite literally pairing silver players with both gold 1 and IRON 3, they're actually quite justified when talking about that coinflip bit on some occasions)
And Plat has been described to me as "I DON'T CARE IF I'M 0/7, I KNOW WHAT I'M DOING, I'M F##KING PLAT! BOW BEFORE ME, PEASANTS, AND DO EXACTLY WHAT I SAY OR YOU'RE ALL REPORTED FOR TROLLING AND INTING!" (I wouldn't know...I'm not plat. >.>)