Huh? I wouldn't call that rude. [There are other things about Nagito he might call rude, but there's no need to jump to specifying examples right this minute. Maybe at a different therapy, when they don't have a search to be getting underway soon.] Humans are very skeletally-shaped, and even have bones of their own. Not all monsters do...

[So, you know, if any other monsters or aliens (cyborg or not) do end up showing up, they might be very differently shaped.]