This is all DRKs get?

[Hruodig]

For the most part you need to be in grit stance, since it gives you enmity that holds aggro and makes healers job easier.
There are bosses that you could turn it off, but you have to keep that in mind, if you will turn it off, it has its consequences if the boss or trial is heavy hitting, healer cannot sustain a wet noodle tank and himself if he and other party memeber will be hit with unavoidable or not AOE. I cannot imagine tanking susano without tank stance for instance, since its throwing out so many aoe's its really hard for healer to keep healing you all the time, you could end up dying even if you manage your cd perfectly.

Keep it in mind, switching off tanks stance does not affect only you, but the healers also even on the boss fights, you will be called for a wipe if someone will notice you are not on tank stance.

You have no clue how tanking at a high level works. Not only is tanking without tank stance expected, but it's perfectly do-able.