Well, I was a bio major, so there were plenty of smart women going into the medical field. There was no shortage of relationships there.
Let's not forget though, if being smart was all you needed to be attractive, I think there'd be a lot of married people around these forums.
And there is that point that they mentioned where they were trying to strike a balance between professionalism and trying to show interest/flirting. Let's face it, there's a lot of silliness and awkwardness involved when it comes to flirting for a lot of people.
I think one of the reasons why people tend to inversely correlate intelligence with beauty is because the time and effort it generally takes to maintain the appearance of beauty or to study enough to be successful in the difficult, advanced level sciences. The common logic is that there isn't enough time for both and that one gives way to the other so it isn't expected when someone manages both.
I think some men would be "intimidated" by a beauty with brains because it means more time and effort to keep such a gem interested and satisfied with him, especially when he thinks of how she must attract the attention of a lot of dudes. Guys are keenly aware of their competition, just as women are of theirs. And in the STEM fields, there are plenty of guys who are potentially as smart or smarter than themselves and of varying levels or arbitrary physical attractiveness. And do you think that, generally, greater intelligence positively correlates with great levels of social skills?
I personally don't find intelligence off-putting, but rather a requirement. A woman has to have more to contribute to a relationship than just her looks. I hate talking inanities and I'm not a story teller or social speaker, so I can't drive entire conversations by myself. Nor would I be comfortable with someone who would expect me to be the sole source of income. Pretty is more 'intimidating' than intelligence in my book.