Debord in this book insists on being obtuse and obfuscates relatively simple ideas. Worse, he would masquerade opinions as reasoning and loves using vague words without defining them, jumping from one possible meaning to the other the next sentence.
This has been my experience with a lot of academic humanities writing in English. I can't take anything written like this seriously. I shouldn't be surprised that other languages would have the same problem.
But Debord's work is not an academic dissertation, nor should it be taken as such. It doesn't present new evidence or advance a logical hypothesis, it merely shows another way of thinking about the things we all know and see; much like so many works of art.
In any case, I think the criticism is much overstated. A lot of the book is quite plain to read.
This has been my experience with a lot of academic humanities writing in English. I can't take anything written like this seriously. I shouldn't be surprised that other languages would have the same problem.