People who can't handle rejection

.

If we're going to talk about rapists, I think the motives of rapists are probably as varied as the motives of sexuals. What you're describing is a camp that is a problem trend I agree, and I would have to learn more about them before I could identify problems (You said parenting could be a factor, but then said his excuse at the end about them being sexually abused as a child was just an excuse). 

But I've heard of other scandals.
Rich/powerful people (Drug lords, shady politicians in crap countries) involved in human trafficing, abusing power.
I remember reading a documentary once about a war, where American soldiers weren't allowed to stop the abuse and rapes of little boys by older men (Who didn't view it as homosexual since they were "on top") which, may have just caused those boys to grow up to be abusers as well creating a cycling abuse culture.

Sexism may be a contributor to rapists (If the people they rape is the opposite sex), but it may be other factors (Power, pleasure, sadism, revenge, intelligence).

It's similar to how sex is viewed differently by sexuals, some view it hedonistically, some romantically, some as an obligated chore, some as a rite of passage, and more. All bull.

Regarding those who can't handle rejection, multiple things could help. Boosting peoples self-esteem. Discouraging obssessive behaviours. Reducing peoples' need to use relationships as crutches. Teaching people to be emotionally independent? Just throwing ideas out there.
And of course, with regards to sex, lowering the importance of sex and dispelling sex as a "controlling force" and "sign of intimacy" could help with that. (I skipped over the obvious "RESPECT BOUNDARIES AND PEOPLE", but there's that too)

Those are ideas, what do you think?