> To me, the main culprits of crimes against usability are business leaders and marketers, not designers (although these do bear some of the blame). [...] However, when you explain the issues they often back down and create usable designs.

Honestly, my experience is the opposite. It is almost always designers who push for what they consider aesthetically pleasing with very little regard to usability.

Yes, when you push back a lot, you sometimes win. But it takes too much fighting, you need to be at powerful position to have the chance to win and they simply do not seem to care about usability.