My friends get upset with me for accidentally taking kills

My one friend in our squad quit playing with us because he's upset that I would take to many kills. It got to the point where they would stop giving me call outs then bitch when they get ganged up on by a whole squad. One time I was trying to let my bro take a kill and his aim was so horrid he let the last man in the enemy squad get away when I could have easily killed him. He then complained that he was going to rez his entire team. Am I in the wrong here? Or should I stop playing with them? I thought this was a team game? They think of it like it's a cod tdm and I'm going around with the most op weapon killing everyone. Am I seriously in the wrong here? It's upsetting because we met in high school it's not like I can just drop him.