Ok, here you go. Saying something "becomes a moral issue" doesn't mean it's immoral. It's means it could be.
You, apparently, have moral issues with pornography, strip clubs and alcohol. Which is fine. Opinions, ********, you know the rest.
As I said, I think pornography and strip clubs are part of a slipperly slope that leads to immoral choices. Do I think porn is immoral? Not so much. Do I think strip clubs are immoral? Not so much. Again, as I said, they may stimulate you but you're left to handle your own business(at least from a legal sense). Prostitution involves another living, breathing being. Maybe that being is making bad choices. Maybe it's just something they like to do and, hey, if you can get paid doing something you like, more power to you. However, it's no longer a solo act. Is it immoral? Not sure. But I think it's a few steps closer than porn/strip clubs.
At the end of the day, sex houses on the corner would make that choice much easier. If the price was right, it's possible that they'd put porn and strip clubs out of business. Our attitude towards prostitution would change. Now, it's for losers that can't get a woman or can't be bothered to try. Legalized prostitution would be something you do before, or after, you go drinking with the guys. "Hey, death, wanna go watch some hookey, eh? We'll stop by ***** R Us on the way and knock one out!"