I've heard some say on topics like this that "it's only a yote" and that doesn't sit well with me or others who want a humane kill regardless of what animal it is!
I would definitely agree with you on that statement. I'm not sure what they consider "decent"...but I'll stick with the larger gun myself.
I work in bio-medical research and when training staff I make it clear that it is not "just a mouse...or just a rat", and they will be expected to always treat them with respect and assure that they have a humane end. That goes for all species.