Can't we say that the same reasons behind the constitutional right to bear arms can be applied to a right to use encryption?

Isn't encryption already considered a "weapon" by the Pentagon?

If this were true then the PhD should quit his job and work as a clerk. No one is forcing him to work as a postdoc.

Note that the clerk cannot do the PhD's job while the PhD, I assume, can do the clerk's job. Thus, there is probably a good reason why the PhD stays in his job.