Why do people think you should defend them at all cost?

I play as support and I have noticed something. Whenever I am with someone and they die they seem to get mad at me for not sacrificing myself for them. They run into a 3v1 gank and if I don't join them with my 300 hp they start spamming you rock in chat. What the hell makes them think it is good for all of us to die just cause they think I should protect them in a fight that is impossible to win? I couldn't tank the damage even if I had max hp cause the enemy teams damage mealts my hp bar. Besides neither mine nor their damage is enough to kill them so why are they going into this gank? Thanks.

Hmm.... so which one is it? Can't be with someone AND they run into a 3 v 1 gank, otherwise you would be joining them, and if you're joining them and refusing to save them, well you just aren't protecting them well enough are you?

You can't do anything about bad team mates. You did the right thing to not help with only 300 hp.

Someone recently created a good support guide. I recommend you check that out. I'll tag you in it.

Dude seriously? I am with someone in the same lane or in a joust and they run into a 3v1 gank they can't win. If I run in to protect them we are both gonna die which is worse than just one of us dying.

Don't mind Kriega, he read what you said wrong. You shouldn't try to help someone who runs into a potential 3v1 situation if they don't have the damage burst to kill at least two of those 3. Like I tell a friend of mine: I can't protect stupid.

Wise words.

As Boogie pointed out, you can't dictate how your team will act, you can only choose how you'll react to their actions.

It's a misinterpretation issue. Happens a lot with a lot of people.

Terminology could be improved. You're 2v2 in lane. A 3rd person comes in to gank (likely the Jungler). Your teammate doesn't recognize the odd-man disadvantage, and continues to fight instead of retreating.

This is not a 3v1 gank. 3v1 gank would be, your ADC is in lane by himself. 3 people that weren't previously in-lane came into lane to gank.

I'm guessing the 3rd man in is what you're describing, and yes, if you're low health due to boxing exchanges, and your teammate continues to fight...not recognizing that you're not in a good position to support without just completely dying, then that's on him, and it's his fault for not being aware enough to see it's a bad situation.