Well, that's... one of those "your millage may vary" type things.
What you find more disturbing, other people might readily accept. I've honestly know parents who don't give a damn if their teens are out having sex, but if they returned home with drugs, oh, no. xD There would be hell to pay, apparently. I've also known people who don't care if their kids / friends are doing drugs, just don't bring 'em home or sell them, and it's fine.
Do I share those values? Hell, no. If they were my kids, I wouldn't want them shooting up, getting arrested, or risking STDs, but I have my own set of convictions and those people have theirs.