Another moral dilemma for you.

Was recently in Amsterdam, (as the starting off point for our 2-week “Rivers of Europe “ cruise). On our first night there, (Before leaving the next day) we had the opportunity of being part of an organised “Walking tour” of the “Red Light District” of Amsterdam.
As you may be aware, Smoking Marijuana and Prostitution are both legalised in Amsterdam, so we are not talking about matters of legality here, simply of morality. So my query is, even if you don’t take an active part in the practise of Prostitution etc, is it still morally okay to go along and gawk at those who do actively participate in it?
Likewise is it morally acceptable for tourist organizations to organize tours of this self same activity site? I ask this because it was only tiredness, the lateness and the wet weather, that stopped me from going along for “my two penneth’s” worth. What would you have done and why?