Please don't make the mistake of assuming media "Personalities" are in control of their on-screen personas. Behind them is an army of manipulators, their employers, charged with ensuring their actors generate and maintain their populist auras. I've never met Mr Grylls, but I am acquainted with a famous person who happens to be a neighbour and, despite her fame, has little control over the content of her programs, or any say in how she's portrayed on-screen.
I'm sure some of you here have gotten involved with TV program makers at some stage; maybe things have hopefully changed now but many years ago, I was flattered to be asked along to a TV production for my expert advice. I was deluded enough to believe they'd be panting at my every word, every suggestion gratefully sucked up and adopted. In reality, they more or less ignored everything I pointed out, and some of the things they put into the scenes "For dramatic effect" were totally daft and unrealistic.
If I'd had any scruples and integrity, I'd have told them to stuff it & remove my name from the credits, but as it happens I was happy to trouser my fee & walk away, confident in the knowledge that no one I knew would ever view the rubbish they'd churned out. Never seen the program myself...