No one is going to take you seriously if your argument is the very reductive "because they choose to" (being tongue-in-cheek here, don't take it seriously)
It is very clear that public image has a huge impact on what people choose. For example, people who consider themselves introvert choose, in majority, to avoid fields that have a strong extrovert vibe. Similarly, people will tend to not choose fields if the field "gives a vibe" they don't feel they belong to. So, if there is an initial bias toward men, the fact that some people don't choose the field is in no way a proof that there is no bias.
I agree that the 10% number is not the best, but the "corrected" number where you take the samples in same job and position does the same mistake. In fact, there are arguments that in these cases, you have a selection bias (some of the men in the field are seeing this field as their calling, but some of the men are just doing it as a job without being overly passionated, while the women that are not overly passionated just don't choose this job) and that using this methodology, women should overperform because there is a gap. The "real" number is probably in between.
It is very clear that public image has a huge impact on what people choose. For example, people who consider themselves introvert choose, in majority, to avoid fields that have a strong extrovert vibe. Similarly, people will tend to not choose fields if the field "gives a vibe" they don't feel they belong to. So, if there is an initial bias toward men, the fact that some people don't choose the field is in no way a proof that there is no bias.
I agree that the 10% number is not the best, but the "corrected" number where you take the samples in same job and position does the same mistake. In fact, there are arguments that in these cases, you have a selection bias (some of the men in the field are seeing this field as their calling, but some of the men are just doing it as a job without being overly passionated, while the women that are not overly passionated just don't choose this job) and that using this methodology, women should overperform because there is a gap. The "real" number is probably in between.