It does seem fairly common for people to think that their profession is something everyone needs to know, and sometimes the arguments are even pretty good. I've met several lawyers who believe that everyone should be legally trained, at least to a basic level, because the impact of law is so pervasive in modern society (even here on HN, a good portion of our discussions are about law).
And that, actually, is a very good point as well: after all, ignorance is not a valid defense! Just because something is common does not mean it is wrong.
