55 HM Mandorian Raiders on my dps Powertech with a merc dps, merc healer, and a Jug dps with a couple attempted pieces of tank gear. After he died once I warned him that it might happen a lot with mainly dps gear. I guess he decided to have me share the load on the big pull before the dog boss, he didn't aoe the spawned dogs, and waited till I had already hit a health pack and blew all my cooldowns to taunt. I had about 200 life left, a dog fart would have killed me off.
At the dog boss I tried to give him tactics, but the dog I marked for me and the other dps to burn was his target. He tunneled it, and we wiped. We wiped a second time because he stopped tanking the boss off in a corner, so he could hit the last dog. Gave him some advice and left. No one else typed anything besides me and the tank so I knew a vote kick wouldn't work. I did whisper him to give him some more advice, to run some dailies/easier content and build a tank set.
Oddly enough this is my first bad tank experience at 55. I expect that kind of gear while leveling, because it is sort of a take what you can kind of thing. Hell at this point all the original 55 hard mode stuff is done on auto pilot. Los is the only tool used, and I hardly ever see a cc.
This wasn't the first tank I delt with that wouldn't ask if they didn't know the fights, I guess they are gun shy because of the habit some people have of kicking any ill prepared tank.
I usually don't find tanks afraid to ask out of fear of votekick. A tank is generally going to have to be horrid to fear that in FPs, considering the queue times for all other classes.
One thing I've noticed though is that in general people are less willing to stick around and help people through content the further along we get in the game.