You've just moved the line of argumentation: instead of "is the word in the dictionary we're using", it's "is that word a bullshit word" -- but only one of those questions is answerable definitively. The only way to play without argument is to use a dictionary, at which point you might as well use the standard one.
(Like another poster in this thread, I do also play friendly games with an open two-letter-word list, to level the playing field for people who don't care to memorize trivia.)
I gave the example to illustrate what I mean by "bullshit word", but the question is more or less this: Are you using this word because it's a word you know, or because it's a word you found in a list of Scrabble words?
I'm not saying that the idea of a canonical word list doesn't make game-mechanical sense, just that it turns Scrabble from a word game into a list of symbols game in a way that seems stupid to me.
It's not meant to be more than an intuitive house rule to encourage people to play with "real" words.
It's a demonstration that scrabble's dictionary uses completely arbitrary and unpredictable methods to choose which bullshit words it has. It can't even use the excuse it's trying to be 'complete'.
(Like another poster in this thread, I do also play friendly games with an open two-letter-word list, to level the playing field for people who don't care to memorize trivia.)