Speaking as a user (I’m not a programmer even if I’m often loafing around here):
Left is not “optimistic” but “assumptive” - blame the dev and the user.
Right is not “pessimistic” but “diligent” - blame the user.
But the worst type doesn’t appear in this pic: they’d put a ball of chicken wire around the label so it’s physically impossible to put it in the hot water.