mocking and quoting bigots I've seen so far
:liberalism: turns to 
"you know it's hexbear when the tankie pronoun parade shows up to force pictures of pigshit in front of you!"* real quick
[*this is paraphrased, I can't remember the exact original quote]
Or "so suddenly I'm Hitler because i think people calling themselves Fae gender is dumb"
Or "why should i need to learn a new set of different pronouns for every person I meet?" (this followed two comments after "I'm literally not a transphobe, I work with plenty of trans colleagues who feel safe around me" (average lib being scratched in real time by having to acknowledge neopronouns))
.
All of these shitheads claimed to be allies when they started interacting but our brilliant pronoun tags immediately made them out themselves as the bigots they are who only pretend to be allies because it looks bad to be openly and proudly transphobic
TL;DR: 
ive met 1 person irl that uses neopronouns at our lgbt community center, I've met maybe 1000+ trans people there because they come to ask us for healthcare providers a lot. we have a sticker printing machine so they can get neopronoun stickers, and its only ever been used that one time
tbh i think a lot of people think it might be too burdensome to use neopronouns in a casual context, so they self censor it and default to they/them which everyone knows how to use.