Maybe because it's a logical fallacy?
If we can reproduce, we should be considered old enough to have sex.
I was 11 when I had sex for the 1st time, I am now 29 and never had kids.
I was not raped. I enjoyed it till I tried anal...shit, shit everywhere. didn't try for a while after that.
And before anyone belittle me for being on 4chan, Human bores me, this why I am single now with too much free time.
The age is not the problem, the maturity neither. The problem for me is forcing someone to do any action (not exclusively sex) and not caring for the enjoyment of your partner. (I enjoy "preliminary" more than penetration now.