Next time, ask for a deposit even if it's just a token one. Explain that others are vying for your time and that you need a monetary commitment. I know that events like this can be cancelled due to weather, something I'm only a little familiar with. Covering weddings, weather is never a factor. However, family days out and about and engagements can be affected in which case for me it is simply rescheduled. I would think that unless it's a once a year event or something of the sort, a deposit can be carried over until the event can be re-scheduled.
As for "rude"? Who knows? They could have been busy. In this day and age emails do still get lost in cyberspace. Or maybe they thought that you weren't at the top of the "important list" that day and had other things and people to deal with first. In any case, it's likely best just to suck it up and remain cordial but in the future try to cement a stronger commitment to avoid it happening again. While good news can travel quickly, it seems to usually travel like molasses. The sonic boom you sometimes hear is bad news spreading. Avoid burning anything because you will never get the chance to tell you side to any potential customers. They'll just assume the bad was the whole kit and caboodle.