The character that Gordon Ramsey puts on for Americans is so wild. Certainly he's to the point and frank whenever he appears on British TV, but he's far from this raging aggressive personality he has on American TV.
I wouldn't really consider them volunteers in any kind of way, as it's a contest where the winner gets $250k and the chance to work at one of his restaurants...
And we (Americans) eat it right up because anyone with a British accent automatically exudes authority and instills a bit of brow-scraping from the frothing masses. Also, a large portion of American has never traveled to other countries, nor experienced anything but domestic accolades and propaganda for their whole lives.
I've only watched a few episodes, but it seems like he's kind to the wait staff and cooks generally, and reserves most of his venom for owners and managers