There is a small group of very vile people in this game. The biggest issue with them is they are vocal. People need to speak up and defend anyone being treated poorly for no reason... and being a first time runner of an instance is not a reason btw.
Tanks are the biggest offenders, followed by healers and then DPS. My guess is queue times these jobs have has a bit of something to do with it. Point is I believe people are afraid of making the tanks mad and getting stuck in an instance with no tank and that is a very likely to happen. However.... you need to do it. You want a strong community? You want a fun community? You want to see more tanks and healers? Stand up to abuse anywhere you see it... Report anyone being abusive.
The community is what we make it and there is nothing SE can do to create an environment that is good or bad.
The best community I have ever been a part of was Everquest. Nearly every "rule" of conduct was 100% community made up. We had camps and they where respected... but that was not something you had to do. People let others camp Rare monsters in piece because that was what the community decided was acceptable.
Those where player built rules, player enforced rules, and they where wonderful.
I recently ran Prea for fun with my new relic. A bard decided he wanted to watch every CS. At the end of the run when he was finally done he was attacked for it. One player who was from my server tossed every name you can imagine at him....
This is not acceptable behavior and I refuse to allow it and you should to. This game is right full of really fun people much like EQ, FFXI and LoTRO. Now they just need to be a bit more vocal.