1) Tanking is rewarding, if one dont like there are various other classes to choose.
2) As long as the tank know how to play you have enough aggro to hold bosses from people with better gear
3) Everyone wants a good tanker, nobody wants to wait the tank to learn how to tank. If you bash the tanks who are learning then yes you deserve suffering, because most of ranged play like braindead and expect the tank to know everything at first try, so they can play as headless chicken.
4)To tell you the truth, for all dungeons you dont need a tanker, I have seen various classes "tanking", whats their difference? They have a fully functional brain.