I definitely see where people are coming from in wanting to separate the Solo from the Party queue, but people are focusing way too much on the negative.
Trolls, jerks, and AFK/Feeders will always exist, even in solo. Is there a chance the 4-man you are paired with will flame and surrender? Sure. But there is also a chance they are awesome and will be helpful. The "issues" with pre-mades will be affecting both teams, too, not just your own.
I've seen a bunch of people complaining about groups only helping their friends, not involving the rest of the team in their plans, and so on. I'm sure it does happen, but again, the opposite also happens. I always duo in ranked with my cousin, and being on voice chat actually lets us help the other lanes more because we can coordinate ganks or when I can roam to mid as a support. We've been able to save the other lanes from losing situations and our games a few times with the extra coordination. Some will say this is a problem because the enemy team will be more coordinated; well, your team will likely be too.
Whenever Riot releases a new feature like this people freak out, but I don't think it will be nearly as bad as people think it will. Our minds go into "worst case scenario" mode way too fast. Personally, I'm excited for the changes to ranked, particularly for the champ select and for the new system for climbing the ranked ladder.