Craig did not play a "brainless tough guy" in Sylvia, Archangel, or The Girl with the Dragon Tattoo. I haven't seen every movie the guy has done but I'm sure there are other examples.
I can see him as a cold, calculating, dangerous Master with a dry wit. You can't because you're biased. It's as simple as that.
A already agreed with you that The Master would suit Cumberbatch as well.