I have plenty of games where I play like ass. That's why I'm Bronze.
I also have plenty of games where I do well in lane, have other lanes that feed, and then teamfights equalize our scores, and it turns into a series of slugfests where I'll die to protect someone who's doing better than I am.
Tell me when the last time you actually played in Bronze was. I don't mean placements where you get matched with random idiots. I mean actually played in Bronze, where you end up getting your ADC to 8/1 bot lane, but it doesn't matter because top's died 5 times and now there's a 5/0 Tryndamere or Yasuo or Renekton just steamrolling through your team that doesn't understand how to safely push waves.
Sure, as a support, you could run away, or stand at a safe distance and heal. Then you're left alone at base or tower or wherever with four members of the enemy team running at you with a minion wave.
OK, give up the tower. Now it's your inhib tower they're knocking down. Now it's your nexus... because your performance in any given role does not make up for feeders in other roles.
Maybe it's like the Anivia game I had yesterday, where I was 5/2 at 20 minutes. Top lane and Jungle produced an 8/1 Jax at that same time, and I don't even know what was going on in bot lane. Those teamfights, try as you might to win them, don't actually work out.
You want to criticize me for "feeding" on every champion? Play a couple of games down here. See how they actually work. Anyone who isn't dying more than 5 times in a game on average is either a smurf or a booster.