I'm not sure what meaning you intend

Ah, glancing at a dictionary, I had intended "Based on or subject to individual judgement or preference" with a splash of "despotic".

As I understand it, moderators are expected to use their judgement, and do not have any firm guidelines on where to apply it. Alicorn recently commented that the best she got for guidance was "ban shoe ads" (quoted from memory).

Yes, if the putative policy you stated above was more prominently stated before, that would help. Notably, if it were on record somewhere, endorsed by those who run the site, in a place where we could cite it and more importantly argue that it's inappropriate and should be changed.