you must detest the Official Scrabble® Players Dictionary

You're right. Not for its being precriptive but for its arbitrariness. Although the OSPD isn't really a "dictionary" at all, just a long (yet limited) word list.

It turns out that words have little to do with the game of Scrabble; what counts is how well you master the list of acceptable-tokens-made-of-letters. Stefan Fatsis' book Word Freak alludes to an occasional non-English-speaking player who nevertheless does tolerably well because of a good command of this list. The book even has at its end a list of the words used in it that aren't really "words" after all, meaning they aren't listed in the Dictionary.

Playing the game casually is fine, but at a high level, vocabulary and even the language itself are irrelevant.

[end of it-didn't-start-out-to-be-a-rant]