Viz, I can appreciate your point. You might say that a Maoist is a kind of communist, and the word
communist would be allowed, so why not
Maoist too?
However, to short-circuit endless arguments about which words are truly "proper nouns", we follow the rule that words must be normally written with all lower-case letters - the same rule that is followed in Scrabble and other word games. Words that are named after a person usually start with a capital letter, and so are not available in Chihuahua.
I can't find any dictionary that offers
maoist with a lower-case
M as an alternate spelling. The British National Corpus has 66 passages using the word, and every one of them gives it a capital
M.
Other languages have different approaches. In the
French language Wikipedia entry for Maoïsme, there are many references to
maoïste,
maoïsme,
léninisme et plusieurs autres mots similaires. Perhaps this is more sensible, but it is not the English way.
Sometimes a word named after a person will eventually lose its capital letter. This doesn't seem to happen very often with
-ist words.
Sadist and
masochist can be written in lower case, and are both allowed in Chihuahua - and in fact
masochist was the nine-letter word in the puzzle where you wanted to play
maoist. But these words are now used in a wide variety of situations, and are applied to people who have not necessarily even heard of de Sade or Masoch.
So, sorry, Viz, but I don't believe
maoist can be allowed. But thanks for presenting your opinion - let a hundred flowers bloom!