He's not saying math is hard in base 10. Moving the decimal is easy in any base. The problem is the base itself.
Items were, and often still are, sold by the dozen precisely because 12 is evenly divisible by 2 and 3. One may split a dozen into 6 of 2, 4 of 3, 3 of 4, or 2 of 6. Quantities of 10, however, may be split into 5 of 2 or 2 of 5. Not as many options for subdivision. Had we evolved 6 fingers on each hand, this wouldn't be an issue.
Likewise, the original article is about harmonising the length of a mile with the sides of an acre, again for convenient subdivision.
Items were, and often still are, sold by the dozen precisely because 12 is evenly divisible by 2 and 3. One may split a dozen into 6 of 2, 4 of 3, 3 of 4, or 2 of 6. Quantities of 10, however, may be split into 5 of 2 or 2 of 5. Not as many options for subdivision. Had we evolved 6 fingers on each hand, this wouldn't be an issue.
Likewise, the original article is about harmonising the length of a mile with the sides of an acre, again for convenient subdivision.