I think they empower you to think outside the box and be on the same page with others.
Seriously, I think a lot of them are just corporatespeak and pscyhobabble. One thing doesn't motivate everyone. As far as sales are concerned I don't think everyone can become an effective salesman (which is what many of these books preach, whether it's selling the product or selling yourself). You can refine your techniques but I believe you either have it or you don't.