Personally, I find that the majority of people in team queues act like selfish solo players without the skills to back it up. I had to revive my members like 3-4 times + buy out twice on my last game today because they kept being solo jerks, and had to face like three times in a row, dying after nine kills or something in one of the intro phases. I'm always cleaning up after others' messes, and then I have to fight multiple people by myself 9/10 times. Maybe what you say is valid if your team mates aren't bad, but that is way too much of a gamble. Solos don't have the variable of these people interfering with your end result.
Don't know. I'm still trying to do ranked in both solos and teams, but it isn't fun doing teams with no comms, no team work, just 1v2, 1v3 all the time. I don't think I've ever played a game consistently that I've been more frustrated with.