Line these teachers up against a wall and whip them for gross stupidity.
Although I of course applaud your sentiments, I have a concern that such a worthy punishment might end up being counterproductive, as such a public spectacle would provide a certain gratification for the numerous teachers there who very likely appreciate 'alternative' sexual habits such as bondage and sadomasochism, as well as those who would be delighted to become a martyr for 'secular tolerance'.
Hopefully, the widespread ridicule that will be heaped upon them all as a result of the publicity surrounding their deconstruction of Christmas traditions will provide an adequate level of shame, and thoughtful parents who had been previously unaware of the leanings of this particular school will rethink any plans to send their children there.