I simply pointed out that with legality (of consensual sex) we could have public acknowledgement of facts and a better chance to address them (which is to say, it was an argument about how best to address moral issues).
You are the one who insisted on making it about the law, regardless of how much harm that law causes.
As often happens, there are at least two effects of a policy, in this case illegality. One is to suppress things that would be better in the open, as you note. The other is to deter such things happening in the first place. The second one is real.
As for the first, I like the idea of some discretion on the part of investigators and prosecutors, though obviously that's not likely in today's climate. But legalization is even less likely.