I asked one of the professors about it once. He gout a big smile on his face and said "Come and talk to me after class." So I did. He would not tell me outright, but I got the definite idea that mere discussion in class was strictly verboten. Of course, I asked for and got this guy on my orals committee.
Pretty sad, actually, when you consider that Hauser's Law has stood the test of time better than 99% of the economic theories out there. Plus, it is remarkably stable over time. Even the most extreme variance is within a +/- 2% range, generally far less.