Do you think backroom meth labs and street-level prostitution would exist if professionalized alternatives were available? How many people have died from tainted homemade liquor purchased in speakaeasies since that type of prohibition ended?

That's the problem with your argument. This isn't a story of a negligent businessman allowing riff-raff to fester. It's a story of a social problem caused entirely by the government, being used to take property from a private business who didn't do enough to help them enforce their destructive laws.