I've spent 20+ years in technical fields.  In my experience, no one prefers male employees to female, nor does anyone believe that men are inherently better at technical fields.  Indeed, the (few) women I know who work in technical roles as proficient as I would expect, given their experience.

In my experience, women tend to self select out of technical roles.  This isn't unique to women - most who start in technical fields move on to other, non-technical (e.g. managerial) fields.  However, women do so in higher proportion.