You should know how to build a team composition.
Rarely are non-smurfs placed here, and short of being boosted, a large portion of the player base have climbed their way into Plat from silver / gold, myself included.
By Plat, “Refusing to Cooperate” should extend to just that… refusing to play with the rest of the team. That includes feeding, refusing to swap, refusing to join teamchat, refusing to synergize with your team, and refusing to fill more than one role.
By Plat, you should have an index of heroes you can play, and shouldn’t just be an insta-lock one trick.
By Plat, you should know that your chances of winning without a tank or healer are slim to none. And not justify that “one time at band camp” that it actually worked.
By Plat, you should know how to swap to counter enemies.
By Plat, you should know what counters you, and why it isn’t working, and be willing to swap to something more effective.
I understand the need for flexibility in bronze / silver / low gold because it’s more-or-less a crapshoot, but by the time players reach Platinum, there should be stricter requirements to play at the top half of the community. It’s insanely frustrating to still be dealing with an incessant amount of one tricks, trolls, and throwers. I climbed from Bronze to Plat by the skin of my teeth, learned different roles, how to play with a team, how to play around a team, and it just seems that it doesn’t matter how high you climb, the community never gets better because there aren’t any parameters in place to make them.
And that’s a sad sign for the longevity of the game.