The reason you should watch P&T is not to change your mind about your beliefs, but to find out something new you were unaware of, to get you thinking. Thinking is not what Penn and Teller did this time around. First they show lots of unnecessary nudity, perhaps to show the glamorous bodies of the hookers. You know guys, not every hooker is a model and where are those ugly ones that exist? Then then start blaming religion within 2 minutes of the opening credits. As it continues, the arguments what people tend to say against prostitution are listed. Over the course of the program these get thrown out, without anyone being allowed to rebuff them, counterargue, or even getting a real expert on the show. Prostitution is legal in Nevada (not within the city limits, they kind of forgot to mention that fact and didn't even start to talk about streetwalkers) and it seems to work really well. Crime rates are lower in Nevada in the first place, even if you have been watching CSI and see all these gory episodes. There are still sex crimes and whereas these farm-style brothels all look really neat, P&T obviously took a trip to Oz instead of having a real hard look at prostitution. Not ever place will turn into some ranch when you legalize it, there will still be plenty of problems and illegal activities surrounding this. I'm sure that ranch is an IDEAL place to have the prostitutes to get their job done.
Prostitution has been made legal in several countries. Over the years there have been significant findings that contradict the list the show throws out within seconds, or never even start to discuss: it promotes sex trafficking; does not control the sex industry as much as you want to; increases clandestine, illegal and street prostitution; increases child prostitution; does not protect the women in prostitution; encourages men to buy women for sex; does not promote women’s health enough; does not enhance women’s choice, and that many women do not actually want this legalized as they will be forced to register and make it public.
I'm not saying these are all bulletproof reasons to leave it as it is now. But these weren't discussed enough and showing a happy farm house in the middle of the desert is not enough to throw out arguments that should be heavily debated before going pro for legalized prostitution. For P&T a more-than-usual biased opinion.