Plenty of people have disregarded the sign (some having no clue it's even there), it's in no way compulsory. It's an attempt at humour, mocking rules and signs

Plenty of people have disregarded the sign (some having no clue it's even there), it's in no way compulsory. It's an attempt at humour, mocking rules and signs in general. On the other hand, I've seen far more odious use of company ski trips, "team building activities" and the like.