> women are not choosing to enter the tech sector
Yes, they're not CHOOSING it. They have the option to enter the tech sector, some: not all, choose not to. In the past women have successfully infiltrated (if that's the right word) previous male-dominated professions, like: well, all of them - doctors, lawyers, advertising, acting, TV ... and the list could go on, and on, and on.
So there is no lack of abillity to break into a predominantly male line of work. The fact that there is little long-term change in women's numbers in IT can only be due to their lack of willingness to qualify for and take up IT jobs - compared to what they've achieved in most other walks of life. The simplest conclusion is that they prefer NOT to work in IT.
Now if you want a sector that badly needs gender-equality for the sake of all the members of society who pass through it in their formative years, lets see a similar campaign to get men (back) into teaching.