Any controller that's ever said "good day" on frequency has decided that the rules don't apply to them either. At least by US standards, that's a non-essential transmission, and therefore "against the rules". Let's fire them all.
The saying "Rules are for the guidance of wise men, and the blind obedience of fools" is rather popular amongst PPruners. Fine, but if you do decide to ignore the rules then you should expect to take responsibility for your actions. This controller will soon be looking for a new job - I hope they feel it was worth it.