I can only speak of my experiences, but I offer some thoughts to consider on this topic. As I've played a little over a year, usually pretty limited, and recently more heavily, my role of support had been taken quite literally. I was buying the wards, using the true support characters, following my ADC to hell and back, and watching as my ADC led us both to a fiery demise in many cases. This strategy--the utopian ideal of supports getting no minions or kills and playing characters that purely support the ADCs needs--has not worked for me. I found myself placing B3, almost B2, then tanking to B5 and being stuck there for a month until I just quit playing LOL for a couple months.
Then I came back. This time, I decided to work on my Zyra game. I decided to build her similar to what I would playing mid. I decided to watch my ADC and if he was playing as I thought he should be (passing the Blitzcrank test you could say: not getting grabbed by every flying arm), I would fill a support role and play in the backseat. If not--as has been the case some 60%+ of the time I play, then I go mid-lane mode. I build damage. I push lane hard. I take as many kills as I must. I will wave clear after ADC has been murdered for the X-teenth time. I will mute him when he starts griping.
And this strategy turned everything around for me. I have in the last couple weeks flown to Silver 5 from Bronze 5, seen my KDA get over 3 on average for a change, my win rates are almost 60%, and the games go more smoothly. I can tell when my actions have helped cinch us the win, and many times, this mid-lane support style has been VERY effective.
Now, I can't speak for Gold. I am under the impression that the games from high bronze through Gold are pretty much the same in terms of people playing their role correctly. I will be able to talk about that more if I can make it to Gold, and I am hopeful/optimistic that I will very soon. I have made platinum my goal, and I might even get there, who knows.
But what I am trying to point out is aggressive self-centered support is a thing, it can work, it can still carry games. It may be the case that your supports are bad and you are good at your role. It could also be the case that your support is playing as he does because the passive support roles and champs just don't work for that ELO as well as they ideally should. There are two sides of the story, and I can only tell you my side. And as a support whose had these debates before from ADCs who like to say things like, "WTF fail supp? Y U let me die and not use all the things to save me over and over?" I must admit that I am inclined to believe it is the bitterness flung on supports from ADCs as a consistent issue that may be the cause of your seeming dilemma.
Just my ten cents. :)