Fear of strangers has no place in Markus' vision of the world. Anything but reckless, he is in fact counting on human kindness. He also rejoices that his muscles alone will power him for ±1,800 days through every conceivable environment.
The problem seems to be that all three (reviewer included) adopt an essentially Newtonian perspective: discover the problem(s); figure out how to fix the problem(s); implement the solution(s). Mostly it's the implementation part which is the obstacle.
I'm not a fan of organized tours or camping. But when you're in hyper-expensive Australia, unwilling to waste zillions on a 4X4, a camping tour of The Kimberley, one of Western Australia's premier sights, may be your best bet.