To get into a position where they were unable to load baggage is unfortunate.
To decide to leave the baggage behind to travel next day, rather than delay the flight and thus strand both the baggage AND PASSENGERS booked on the next flight makes sense, unpalatable as it may be to the affected passengers.
To not tell the passengers before the flight is pretty rude, but understandable; the potential for conflict with angry passengers onboard would seem real, but it did deny passengers the opportunity to decide not to travel.
But to leave a plane load of people hanging around a carousel for two hours waiting for luggage which you KNOW will not appear until next day, presumably simply because nobody wanted to be the one to break the bad news, is to me as a potential passenger, unforgivable. Someone senior in a uniform should have been out there as soon as possible explaining what had happened, when the bags could be expected to arrive, how the customers should notify where they want them delivered or forwarded, and what compensation they will be offered.
That's the point where I decide I no longer fly with you if I can possibly avoid it.