That is actually the least intellectual way you could approach the issue. You are relying on people self-censoring (and we may see some downvotes to provide some real censorship). But I will give you the uncensored answer. There are, in fact, a number of possible reasons apart from the one you have in mind. Here are some.

1) Tech is meritocratic so it attracts men who are less physically attractive or socially capable, because they mainly need technical skill. This in turn makes the field less attractive to women.

2) Tech is a monotonous job with low social status, and so it attracts people driven by ambition and desire for money, who tend to be male.

3) Women are fundamentally less interested in technology because they prefer fields with human interest (though this doesn't explain the gap between programming and, for example, math or physics).

I have only really addressed the gender issue above, but I think that's enough to critique your original way of phrasing the problem.