The primary point is that the now-standard pedantry about less/fewer is in fact one of the many false "rules" that have recently precipitated out of the over-saturated solution of linguistic ignorance where most usage advice is brewed.

But not the usage advice at MWCDEU. This is the start of its entry on less/fewer:

Here is the rule as it is usually encountered: fewer refers to number among things that are counted, and less refers to quantity or amount among things that are measured. This rule is simple enough and easy enough to follow. It has only one fault—it is not accurate for all usage. If we were to write the rule from the observation of actual usage, it would be the same for fewer: fewer does refer to number among things that are counted. However, it would be different for less: less refers to quantity or amount among things that are measured and to number among things that are counted. Our amended rule describes the actual usage of the past thousand years or so.

As far as we have been able to discover, the received rule originated in 1770 as a comment on less:

This Word is most commonly used in speaking of a Number; where I should think Fewer would do better. No Fewer than a Hundred appears to me not only more elegant than No less than a Hundred, but strictly proper. —Baker 1770

Baker's remarks about fewer express clearly and modestly—"I should think," "appears to me"—his own taste and preference. [...]

How Baker's opinion came to be an inviolable rule, we do not know. But we do know that many people believe it is such. Simon 1980, for instance, calls the "less than 50,000 words" he found in a book about Joseph Conrad a "whopping" error.

The OED shows that less has been used of countables since the time of King Alfred the Great—he used it that way in one of his own translations from Latin—more than a thousand years ago (in about 888). So essentially less has been used of countables in English for just about as long as there has been a written English language. After about 900 years Robert Baker opined that fewer might be more elegant and proper. Almost every usage writer since Baker has followed Baker's lead, and generations of English teachers have swelled the chorus. The result seems to be a fairly large number of people who now believe less used of countables to be wrong, though its standardness is easily demonstrated.