Neglectful / high threshold. A post or comment has to be extremely one way or the other for me to click one of those arrows, and as for boosts, basically forget about it, even if they are the right thing for stellar content. I would like to give out more (of all kinds), but never seem to be able to bring myself to do it.
I think seeing a ratio that already looks right might play into it a bit (since I’m on an instance that shows both up and down), but there are plenty of 0/0s that don’t get anything from me either.
Getting into the further “why” is deep existential, psychological stuff that’s probably well beyond the fluff level of an internet points discussion, and I might not even be able to begin to examine that without the help of a qualified therapist or something.
Check the backs of the handles. Sometimes a manufacturer will stamp their name there. Or the name of the restaurant they were made for, but that’s less common, I think.