Crap that makes me mad:
1) People who don't go to their waypoint. I don't mind if you go chase down a skulk/fade/gorge/onos, but I want to see you back at the WP after that.
Pissed off example: Team of four HA chase down an onos into holo from processing, kill it. I order them back to upper processing. They just stand there. Reissue wp. Standing there. Tell them over text go to WP. Standing. Commander has left the chair.
2) People who say "OMj C0rnm4nd0r j00 5ux0r" when they couldnt comm their way out of a paper bag. I've had a guy tell me I suck as a comm, I eventually got out of the chair from #1, he gets in, drops a TF two feet from the TF i already dropped in the base, spends about 100 res on turrets (and still leaves a blind spot on the TF he dropped).
3) People who say "owned" after every kill.
4) People who don't build stuff. Final siege on ventilation hive on hera, I have phase, tf, etc built in maintenance, I drop an armory, three people ignore it (we have something like 300 res, I'm not worried if they die) so when they go in and scream for ammo I tell them they should have built the armory. Thus my phrase "I don't drop stuff for you to stare at it, build it"