The data available shows that women and minorities ARE under represented in the tech industry. Corellation does not imply causation, but if you have a limited number of causal factors during the hiring process, the logical conclusion is that parts of the hiring process contribute to this under representation in significant ways.

Perhaps the focus is wrong. Perhaps it's not the 'technical' part of the technical interview that causes this disparity. Perhaps it's just good ol' fashioned racism or prejudices, and really the part of the technical interview that causes a disproportionate number of white males to be hired is simply the fact that the interviews happen with the interviewer fully cognizant of the applicants race and gender. You'll notice that the article also mentioned their disdain for being able to see the applicant.

To dismiss a fact that reasonably straightforwardly follows from empirical evidence and limited options for causality is simply obstinancr.