Let's not forget that all the scar-faced guys (Shiro, Dad Kogane, Kolivan, and Zarkon ) are also the dads/leaders. The gremlin hates dads.
I mean we don’t know if Sendak and Kolivan are dads but. Being a leader figure and/or dad attracts the gremlin.
…Sam Holt, wherever you are in space, guard your face, man.
(we also don’t know if Mom Kogane has a facial scar because she is pretty clearly some kind of rowdy knife-party parent so it’s possible the gremlin is gender neutral and despises all manner of parents)