Sometimes, even when you do try to help the tank, they just don't listen. I got in Haukke on join in progress sometime ago, while leveling my bard. The tank was alone there, and we got soon a healer and another dps.

The healer, the other dps and I; tried to explain what to do, the tank was a gld (I have one, so i know the logistics), and I tried to explain how to do rotations and use flash and similar.

They didn't know what flash was. We did stick with them to the end, but we didn't arrive to beat even the second boss, because we kept wiping and they were not able to hold aggro at all. Even with healer explaining over and over again what to do.

I am all for helping new players, but in that occasion, my advice in the end was: try other roles aside tanking, maybe you aren't fit for tanking.

But i completely agree, sometimes, just needs to explain stuff, I was lucky I improved tanking because i met awesome people who actually explained what the hell I should do.