Yes, I can agree with that.
In Plat, from experience, people tend to (just like you said) have the potential to make incredible plays, but not only do they constantly fail to live up to your expectations, they also think they're entitled to at least high Diamond, not Plat, so they behave like total goddamn assholes.
Silver is worse, but in a different way. People there feel demoralised from the mere fact that they're Silver, and not Gold (something a lot of Silver-ranked people dream about every night), so they give no fucks about whether or not their mechanics are equal to those of a guy without arms, or if they'll feed and quit. They just lack the fucks to give about the game itself, mostly out of self-pity or on the other extreme end - complete self-centered behaviour, even more so than those Plats.