Moral argument: functioning society's don't expect their member to act perfectly and always make the right choices. Would you expect a hospital not to treat you because you got injured while committing risky behavior (e.g. extreme sports, trying strange foods, or arguably driving a car)? Treatments like this support "repeat offenders" and the poor bastards who make a wrong choice once alike.
Pragmatic argument: It's better economically and for productivity for people to not have HIV, Syphilis, etc. It's far easier to provide treatment and testing then to tell people to stop having sex.
Pragmatic argument: It's better economically and for productivity for people to not have HIV, Syphilis, etc. It's far easier to provide treatment and testing then to tell people to stop having sex.