I call all 'no-kill' TNR charlatans liars based on extensive experience.  If you're not one, this doesn't apply to you.  If you are, it's simply reality and has nothing to do with my "heart" concerning the matter.  It is what it is, as you young folks like to say.

Oh yeah, there were 15 human cases of bubonic plague in the US last year, and the State of Hawaii Dept. of Health Disease Outbreak Control Division maintains more than one fact-sheet about plague.  Perhaps they're concerned about irresponsible people bringing infected cats to the island.

And it terms of ecological stability "native" vs. "invasive" is a very important issue, whether you think so or not (there are no native rodents in HI, BTW).