The thing is, toddlers don't know when Christmas is. They literally have no idea what day of the week it is.
So this isn't for their benefit, is it? If you have toddlers and you have to work on Christmas Day, you just move your Christmas Day to another day in late December and your kid is literally none the wiser.
And if you have children who are old enough to know when Christmas Day is, they're also old enough to understand that Mummy or Daddy has a job which unfortunately doesn't stop just because it's Christmas, so this year we are going to do Christmas on Boxing Day instead. Or open presents on Christmas morning before Mummy goes to work, then have pizza in the evening when she gets back, and do the big Christmas dinner on Boxing Day. Whatever.
In fact, there are probably at least a million children in the UK who have some sort of Christmas Day on a day other than 25th December every year, because their parents are no longer together and they can't celebrate with both their parents at once.
So this is really not the big deal that some people seem to be suggesting it is.
Children aren't going to be traumatised by the fact that their parent had to go to work on Christmas Day some years. They are traumatised by actual abuse and neglect.
What does worry me is what kind of children these entitled parents who think their Christmases are more important than those of their child free colleagues are raising.
Because if you, a grown bloody adult, are stamping your foot and shouting, "It's not FAAAAIIIIIRRRRR!" when your colleague says, "no, I won't swap shifts with you and work on Christmas Day, I have plans", how are you teaching your children to share toys, how are you teaching them to deal with disappointment, how are you teaching them that the world doesn't revolve around them and that they can't always have everything they want in life?
I assume that you are not teaching them these things, and that you are raising spoilt, entitled brats.