@DeeCay_DK_81 All of the things you said, and more--and let me add the jocks who constantly belittle players who aren't as skilled as they are.
At the end of the day, it's a GAME! If you want to play with pros, exclusively, befriend more pros and party-up on pro servers--but please don't beat up on the 15YO kid who just got his first XBox for Christmas and is still learning the ropes. Instead, you could probably become someone's hero--and make a lifelong gaming buddy (I have quite a few)--by helping them to learn and improve.
But I digress.
It has gotten to a point where "mute all" is one of my favorite settings in MP games. I have very little tolerance for people with poor microphone etiquette, so they immediately get muted--or I just back out of the lobby, altogether, and find a new one. Private party chat is much preferred.
Until some gamers grow to be more respectful, united and helpful to one another, that's how it's going to stay, for me.