Tanking is easy and relaxing i guess for me. Being a tank actually gives you more freedom to ignore many mechanics in a fight.
And it's easy commendations too, I find that people appreciate tanks more than healers.
I already have 861 commendations in only 51 days of game time being a tank and i spent most of it AFKing for hours and hours, while my dps oriented friend only get about 600-ish in 470 days game time.

First time in some dungeon? Go tank!
First time in some trial? Go tank!

Go tank!

(but don't forget to say that it's your 1st time)