I main support and I agree totally. If I solo que, I will lose non stop because I have to rely on my team. If I get a lousy ADC (which happens all to often due to people picking it first because they have "pick order" and get countered) then bot is lost, and they blame it on a bad support. If I duo with friends who play ADC, I typically win those games because I know my ADC will be fed and protected.
I recently started rank, and am still in bronze. I have made it about 3/4 way to bronze 3 when I decided to try some solo que's. As you have probably guesses, I am back in bronze 5. It is hard to play support if you have no 'support' from your team. We are a different type of carry, and people don't understand exactly how support works. I seriously believe some people honestly believe supports are supposed to have god mode cheats on hand to keep them from dying, because we are afterall the support.