In short, these things sell because American business leaders fetishize these sort of ex-SEAL types.
It's all a little much for me. Not to mention unfortunate, because the sort of leadership that works best in the military is decidedly not the sort of leadership that works best in business. The military demands that soldiers immediately and unquestioningly follow commands given by their superiors (particularly during combat). Lives are literally at stake, so any hesitation for even a moment could spell doom.
Meanwhile, in business, I strongly believe leaders need to be in more of a team-servant role -- yes, motivating, providing vision, etc., but also cultivating a sense of "your voice matters," if that makes sense. Being a 'force multiplier' in business requires a different mentality than in war zones.