This rule also is very easy to remember and identify (like split infinitives), and it exposes social aspects of learning and pedantry. Showing you know this “rule” means showing that you are among the group of people who care in this particular way about language.

There is often a not-too-subtle corollary that others don’t care, or don’t know, or were not educated. Like so many markers of class, it becomes a signifier of “us” as opposed to “them.”