I love playing support, but the stuff you have to put with sometimes when supporting is ridiculous. Some people don't seem to realize that you don't get infinite starting gold when playing support. They also seem to assume that by playing support you can be everywhere at once. Defending top tower alone? No, you should be warding our jungle in bot where our Doom is jungling and can't be bothered to look at the mini map. And sandking dying 17 times must be part of some masterplan I wasn't aware of.
Some games are just so demotivating :/
As someone who generally plays the support role 99% of the time, I can tell you that the mute button is your friend.
A couple days ago there was a dude who within 5 seconds into the game was barking orders at the supports to buy wards and the courier...going as far as specifying who he wanted to buy what. When I told him "Yo, we got it"...he replied with "No you don't". This was literally 5 seconds into the game! That dude was on mute immediately, and we did great that game.
I try and accommodate reasonable requests, but you do need a bit of thick skin to play the role. A lot of people think that if you aren't doing specifically what THEY think you should be doing, that you're bad. Mute!
I speak a lot on the mic, and ping on the map with relevant data. Calling items people may be building if its important (blink dagger, BKB, etc), calling missing, stating if my lane needs a gank or if we're losing it bad.
I find that just doing these things should show people that you know what's up, and at that point the only typical complaint will be that wards aren't up. Knowing that I'm generally always buying wards when they are off cooldown, a casual reminder that they are on CD or on the way or about to be planted should cover it.
Over communicate, liberally mute.