Intuitively one might think so, but in practice the drug tourism money isn't as important as you would think. I would even go so far as to say that legalizing prostitution in other countries wouldn't impact the Netherlands' tourism much either.
It's mostly just part of the country's (and Amsterdam's in particular) reputation. Let's put it this way: you can legally obtain cheese and wine in most parts of the world -- even French cheese and wine -- but that doesn't stop people from associating France with cheese and wine (whether when in France they actually consume it or not).
It's mostly just part of the country's (and Amsterdam's in particular) reputation. Let's put it this way: you can legally obtain cheese and wine in most parts of the world -- even French cheese and wine -- but that doesn't stop people from associating France with cheese and wine (whether when in France they actually consume it or not).