5% of the Netherlands GDP comes from the sex trade, so yes there would be some strong incentives to say positive things about it. Actually given the huge amount of money made by the sex trade world wide, I'm amazed that there isn't more propaganda about it being so great. Perhaps that's because the johns quite like it seedy?
Oh, and having brothels doesn't mean no pimps. There are often pimps too (see the Nevada links - pimps apparently drive in more business and keep the prostitutes in line) or the brothel keepers pick up that role (again see Nevada, or the findings about Victoria, Australia).
I too thought of course legalisation would be the answer, but the evidence seems to suggest that places with registered brothels have an even larger underground scene, and even worse treatment of prostitutes.
And in any case I really question whether nomalising buying women for sex is a good idea in any way shape or form. Look at the impact of the growth of lap dancing/strip clubs etc? It's not very civilising is it?
Interesting that the only place that has made the buyers of sex the criminals has a parliament with more women than men, and a long history of equality. Oh and yes we probably shouldn't compare Amsterdam with Sweden, but the comparisons with Finland (also not somewhere you immediately thing - great I'll go there and buy a prostitute) also hold true on sex trade related crime (principally trafficking).