"So you think things like drugs education, education about stds, contraception etc should just be stopped because some of these kids might already know all about it and they might not get pregnant so, hey, why should we get involved?"
No I don't, I've not even mentioned any of those subjects. I think all the things you've mentioned there should stay, so I'm not sure why you think that I feel they should be stopped.
"I think your position is bollocks. I think you have no way of justifying why an 18 year old should refuse these compulsory classes so you have moved on to 'but hey, it's a free country and we can't be sure he might end up raping someone "
This is the thing, you seem to think he has to justify his choice not to go, but he doesn't. He's the only one who suffers if he doesn't go to this workshop, why is it any of our business, and why do you think he has to justify his personal life to you?
I already gave a justification why some might refuse the compulsory classes, but you dismissed it out of hand. So your statement that I have no way of justifying it is incorrect. I did give a justification, you just ignored it or decided it was wrong.