I tend to agree. I think this attitude is something of a holdover from the early days of computer science, when of academics from all the other, existing fields, mathematicians were usually the best fit. Now that we have formal computer scientists, computer engineers, and software engineers, this is no longer the case.

In my experience, when someone from a purely mathematical background tries to program or explain something for programmers, they often (but not always, to be fair) insist vehemently on sticking to methods and algorithms that at best confuse the issue in a programming setting, and sometimes even run counter to how the computing hardware works, reducing performance. In these situations the rationale given is usually something along the lines of, "Listen, we mathematicians have been doing it this way for X hundred years, so that's the way it should be done!"