* the rest of STEM,
* the law,
* medicine,
* pretty much all the rest of the professions (accounting, actuary, &c)
... despite the fact that many of those fields are, both intellectually and from the amount of work product expected, more challenging than computer science.
Add to that the fact that most software jobs are far more work/life flexible than other professions (roll in late, work from home, wear whatever, weekly+ deliverable cadence, &c).
It is difficult to come up with an explanation for the 82/18 split in this industry that doesn't primarily include an implied preference on behalf of industry incumbents to avoid working with women.