The thing which comes across most strikingly to me is this "And we parents hand over the tussle over schoolwork, computer games, condoms and hashish pipes gladly for huge sums to the professionals.” Some might, this is not the reason most parents I talk to chose their independent boarding school for their children.
I assume the topic of UK boarding school vs high quality German state school has a particular resonance in Germany and that's why the article was published over there. If he were simply saying is a "top" boarding school value for money against a very good UK state school then would the Telegraph have bothered printing it? Hardly controversial.
As it is it comes across a bit as if they want to drum up a bit of " 'e comes over 'ere , criticising our schools " to me.