I'm not all that competitive, while many feel that competition brings out the best in people I tend to believe the oposite. That doesn't mean I don't strive to get better at things and value winning; just that winning to me isn't as important as having fun.
However, when I'm playing a game that involves me being on a team my goal is to help the team. That doesn't mean that I rack up the most kills, complete all of the objectives etc etc. What that means is that if I see a team mate getting shot at from someone I try and help them take that person out. If they are being attacked by two people I try and take out the one they are not going after.
I would just like the same when I'm in those situations; and frankly it rarely happens outside of co-op play. It does get worse when you have 2 people carrying on a conversation in VC that has nothing to do with the game being played, all I ask for is a little respect.
As far as noobs go I would never talk trash about them, simply put I was a noob once too; as was everyone else playing that game. If a new player doesn't know what he/she is doing, accidently kills me or other team mates I chaulk it up to a learning experience.
As far as outside circumstances, well I deal with that every day. I game and take care of my 3 month old at the same time and sometimes it makes playing difficult and thats not including the significant drop in my skill because of trying to do both at the same time. I however try not to be such a burden on my team because of my situation, if I'm on VC and my son wakes up screaming I mute my mic. If I need to pick him up and try and hold him while I'm playing I put myself in a position that keeps me safe until I can pick up the controller again. If I don't think I am going to be able to put a good effort into playing the game I will leave to open the spot up for someone who can.
So when I am playing and my son is asleep next to me and I can focus on the game in front of me I would just like to know that the people I'm playing with want to play the game...not joke around about a party they went to last night while I'm getting slaughtered and they are off in the middle of nowhere.
When I'm playing Co-op with a real life friend we will hold conversations during play over VC but that is only because we are the only ones in the game. If a random person joins our team I'm not going to subject them to our conversations about "Hows the house?", "Get your taxes done yet", "What ever happend to BJ Trisha and her sister Easy Lisa?"