it is quite paradocical: Martin Luther invented the Christ Child for his Protestants, as he did not like Catholic Saints like Nikolaus.
But what happened?
The Catholics just adopted the Protestant Christ Child, while staying faithful to Saint Nikolaus still.
And they adopted the Christ Child so whole-heartedly, that the Protestants got confused and thought that the Christ Child was Catholic!
So they turned away from the Christ Child and adopted the Weihnachtsmann = Christmas Man.
The Weihnachtsman imho is a mixture of Saint Nikolaus and the old Germanic god Wodan or Odin.
And I can prove it! :)

So now we have the Protestant Christ Child in the Catholic South.
And the half-Catholic half-pagan Weihnachtsmann in the Catholic North. :)