The term as used might not be consistent with a specific definition, but I’m pretty sure this wasn’t about “technically, that isn’t the correct term to denounce his sexual abuse of minors with” so much as shifting the goalposts for what counts as sexual abuse of minors in the first place. It’s a shorthand, and both parties agree what it’s short for, it’s just that they draw the lines for that thing differently.

So no, it’s not that people “hate to think things through rationally”, because rationally thinking things through makes it clear that the context isn’t a scientific one, but a moral and legal one. It’s not wrong, you’re just emotionally attached to a specific meaning.