None of them have gone crazy like in this story and this outcome is hardly apparent. Most are nice women that I'm still friends with. Maybe it's more common in the American college scene - there certainly seems to be a moral panic going on there. If you take a lesson from this, it's probably closer to "avoid American women" than "avoid younger women".
As for whether it's "weird", it depends on how you look at things. A lot of folks are fairly restrictive in the categories of people they interact with - I know several people who can only deal with very intellectual sorts, for example. E.g., they'd never date an anti-intellectual type (religious, feminist, etc), an unintellectual woman who seeks to enjoy life, a woman of a different socioeconomic background or even a woman at a different stage of life.
I don't view things so restrictively so I can enjoy the company of all sorts of people. Then again I'm also pretty weird so for me being super restrictive might simply result in being forever alone.
Look at Patrick Stewart. How many 70 year olds would marry a woman in their 30s if they actually could?
you're implying that love is based on rational thought in the first place