Because they aren't considered to be as desirable of jobs? Same reason women aren't generally complaining that they're not as well represented in coal mining, oil rigs, construction, etc.
With the exception of teaching in your examples, nobody really cares that there exist jobs that tend to attract one gender over another. What matters is if the better jobs only attract one gender.
There was a big push to get more men in nursing a decade ago. Hospitals offered big hiring bonuses and 100% tuition reimbursement after a couple years' employment. There were billboards on the side of the expressway talking about how it wasn't just a woman's job.
I don't know how successful it was, but I would have jumped on it if I wasn't close to finishing a CS degree already.
With the exception of teaching in your examples, nobody really cares that there exist jobs that tend to attract one gender over another. What matters is if the better jobs only attract one gender.