Yelling "HEAL!" or other criticisms of the healers. While it is possible the healers on your team are bad, one or more of the following is more likely:
1) They are overwhelmed. You might have too few healers, or their level may be such that there is not much more they can do.
2) They are constantly under attack and/or nobody is helping them shed attackers.
3) You simply charged ahead foolishly, got focus fired, and were out of healing range or (rightly) deemed not worth healing due to your own recklessness.
4) The other team is simply better. If the other team is delivering ferocious DPS, your healers will simply be unable to keep up.
Insist that the only way to win is to hold the Fort. I think this has been addressed sufficiently, but it really needs to be driven home.
Calling your teammates stupid, noobs, fools, or any other insult. Tier 1 is a chance to get to know people on your realm. These are people you may be fighting with for many months or years to come. They may be learning how to play MMOs for the first time, or learning a new class archetype. No matter how badly you think they are playing, these are your teammates for now and perhaps for the future. Helping them learn is a much better idea than criticizing them for failure. Furthermore, the failure may be your own and not theirs. In RvR based games, your reputation is more important than on purely PvE games. Being liked simply by 25-40 people in your guild that you raid with is not enough. You will need to be able to work with hundreds of different people if you have any hope of success in large, open world RvR.