I don't quite understand this. First, girls play video games. Everyone plays video games. Second, are you saying that portraying female founders in sexist terms is immaterial because whatever explains women being rare in tech has already taken effect after the age of 5?
That would imply that sexism in media only merits attention at all if children 5 or under can see that media. I think that's pretty unlikely.
And what about being a decent human being to the women who are already here? I mean say for the sake of argument that we go along with this theory that something utterly irrevocable happens at the magical age of 5. Doesn't a perfunctory nod to public decency still require that, if a woman in technology says "this article about women in technology does not portray people like me in the way I would prefer," anyone who is not in that category should acquiesce, or at least show a baseline level of respect for the request?
When I was a raver, and I saw stories in the media about ravers, and I told my non-raver friends "yeah that doesn't quite correspond to reality," they were curious to hear what the reality was. When, as a first-generation American with British parents, I spot some unrealistic British character on an American TV show doing something no British person would ever do, if I point this out to Americans, they tend to listen.
I think you have to just show respect for the fact that somebody in the category that the article was about disagrees with the depiction of the category. I think that's (no pun intended) categorical, and the larger issues of sexism are irrelevant here. I think that's just common courtesy, even leaving aside your argument that media only has an effect on the mental attitudes of children, and/or that the whole thing is a done deal by age 5 anyway so why bother -- OK honestly I have no idea what your argument was there. But I made a good-faith effort to tackle it and I think any discussion of women in tech should show a token level of courtesy, just on the offchance that they turn out to be human beings after all.