Yeah, yeah. The support's main job is to peel, shield, heal and all that, but please don't expect them to always be there to cover your ass.
I can keep you alive when the enemy team tries to Zerg Rush you (for the most part), but I can't ensure your continued safety if you, say, dive headlong into the entire enemy team, alone, miles ahead of your team.
Another thing, if the enemy has a super fed assassin, I'm not going anywhere near that has an enchanter. You can call me a coward all you want, but I ask you, what's more useful to the team; a support that's applying shields from the back or a dead one?
What I'm basically saying is, if you die and your support lives, instead of going into all chat to %%%%% about them, or spam pinging them until you're blue in the face, think to yourself; could they have actually saved me, or did I just throw myself into the grey tinted void for no reason?