The problem with Thrun is
>Oh man, he'll totally shit all over every control deck ever!
>Wait, didn't Wizards print an efficient, black fatty..?
>Oh, fuck. Well then...
Thrun can't get past Grave Titan. He can't stop Grave Titan. He can't do enough damage for his mana to make it worth even considering to deal with grave titan.
And then there's frost titan, who's the worst one, and can still at least make Thrun's life irritating by tapping 3 lands if Thrun wants to block. 1 if he doesn't.