Rude people are rude. I recommend to just ignore them. I remember just seeing your topic about just starting this game. Not all of the people who play lockdown are like that. Just try your best for team, and if you don't do well, who cares? It's one game, you're still learning. Running back to get health could be more helpful than dying if no Guardian is around, as Juances mentioned.
I still get told I'm bad because I usually stay at 8000 or lower damage because I capture points more than anyone else I know. I can end a small round with up to 8 captures on a regular game. They tell me I'm bad for not doing enough damage, and it's even worse if you lose. The people who bully you are just frustrated with themselves. Don't give them the satisfaction of letting their intentions work.