I think you’re absolutely right about the ambiguity, though. For one, people who’ve declared war on “moe” often use the word in a different sense than people who declare their undying love for “moe” do (the “moe” of Hyouka seems to me to be a different beast from the “moe” of K-On!). And the things that people try to use as a replacement—I’ll use “mature” from up above—often mess things up thus: one person wants something “mature”: thoughtful, subtle, less flashy or gaudy, more substantial (note how many of these words are ALSO vague!), etc. while somebody else also takes the word “mature” as a good thing, but uses it to mean violent, gritty, “hardcore”, pessimistic, etc. (Note that these two definitions are not necessarily incommensurable.) And when you’ve got an essentially collaborative form of art, it’s important that everybody agree on what they’re trying to do when they want to make their show “mature”—or “moe”, or anything at all!