Earlier quoted context omitted.
I think the rise of males in CS was due to the rise of the personal computer. As someone noted earlier, as computers become more common in the home and males started using them, they picked up a stigma associated with the type of males that used them. Why does that have anything to do with primary school teachers? I'm fairly certain very little.
Because it's only a "problem" when an industry is male-dominated it seems. Question is do we want equality, or not?
There's a lot of talk about gender transitions on jobs. One common argument is if men leave jobs as they begin to pay less or is it that as more women take to a job, we value the job less.
Outside of a few niche industries (modeling, porn, etc...), men generally are in higher paying industries. And gender transitions within industries tend to favor men (for whatever reason).
I don't expect men and women to participate equally in every field of employment. But it would be interesting to understand why women aren't represented as highly in some of the higher paying fields, especially since the opposite is almost never the case (women are over-represented in a high paying field).