Most complains (not mine, I don't mind premades even though I solo queue 99% of a time) are that solo queuers/causals/bads, whatever the name, feel that facing a premade/people with beter gear/using voice comms is unfair. It should fix that unfairness, wouldn't it? It would also allow people to more realistically asses their current level of ability. Team ranked would be still top-of-the-top for pros in pvp-guilds like you, but for :foreveralones: like me, solo-only ranked would give us more fair or "competitive" environment to play in.
Works in other games, dunno why shouldn't it work in this one.