This reminds of a a study, where in a way it's the same as what your 'colleague' is saying but without the aggressive insulting bias.

It looked at savants, and found that male savants tend to be really great at one thing, while female savants tend to excel with a larger range.

Basically, if a man is really great in mathematics, he will not likely excel in anything else, and therefore pursue a career in mathematics because that's his only option.

Meanwhile, if a woman is really great in mathematics, she probably does well in a broader range of fields comparitively, which means when it comes time to choose a path, she has more options available to choose a career which better suits her interests or desired lifestyle, which typically would be a more social field.

This isn't necessarily why women would be dropping out during year 3-4 however. That could be due to a number of factors.

For example, it could also have roots in another study. It took mothers with infants and asked them to adjust a ramp based on how steep an incline they thought their child could successfully climb.

The mothers cosnistently placed the ramp at a lower incline for girls than boys, despite that the control found children at that age were of the same ability.

This suggests that at least parents if not society implement higher goals for boys, and reduced goals for girls. This would presumably resonate through development and lead to women underestimating their own abilities or being underprepared for adversity, and conversely to better prepare boys.

Ultimately though, if someone can't have a discussion without blanket insults and a generally agressive attitude, I wouldn't bother.

Its also interesting how such people are also so obsessed with insults based around physical appearence and sexual activity. Always seems like someone projecting.