I play support...a lot...like...A LOT.
Yuumi, Rakan, Pyke, Leona, and sometimes even Thresh.
And I manage to keep my death count relatively low in every match while also providing what I can for the team. There are instances in which I will allow my champion to die to save a team carry, but only if I am confident the sacrifice is needed and doing so will ensure the survival of said carry.
I don't take my allies jumping into every bad scenario as an open invitation to take a flying leap off a bridge right alongside them, okay?!
And I sometimes receive hate for it. I've been called a coward for it. I've been told I suck for it. But I really don't think so...because I know what my champions can and cannot accomplish. I am not perfect at doing those things, but I am familiar enough to know when trying to do something will absolutely result in failure. And I avoid doing those things. And because of that, I don't end my matches in double digit deaths.
By staying alive for as long as possible, I ensure that my team almost always has at least one living ally on the map so that something of value can be done even if it's something small like clearing a wave of minions to safeguard turrets while I wait for allies to re-spawn or placing down vision at key points in the jungle. I ensure that I am ready and able to assist allies in securing kills and objectives provided that it is the right opportunity to do just that.
Supports should not be treated as or played as meat shields for the rest of the team so that allies can do whatever the hell they want whenever the hell they feel like doing it. They should be held as accountable as any other player on the team for the mistakes made on their part. Not every death is a mistake, but most of them are just that, mistakes. And being a support does not automatically excuse any player from that.