Earlier quoted context omitted.
The salaries aren't low because of equality though. You're just shifting the high earners from the people doing the work to the managers of the people doing the work.
As far as my experience goes, managers make about the same, or less, as an engineer at a similar experience level. They may end up at a higher compensation level if far enough in the career ladder, but I don't think it's significant in the bigger picture. The average CEO earnings in the Netherlands, including bonuses, is only 5x-6x the average engineer salary.
What do you mean by average CEO? That's about the same as a CEO of a mid-sized American company. Shell's CEO makes a lot more than that, even considering the terrible year for oil.