You my friends are suffering from seeing racism where is none. I'm guessing you are talking about the snowdown skin line, and I'm guessing you are talking more specifically about the ones that have to do with Santa skin which you consider "Christian" despite have nothing to do with it, Santa Claus or whatever name is known locally is recognized globally (even on countries that are not christian) and the snowdown thematic is carried around the world (winter snow, red hats, etc) even if in some countries December is actually summer time. Even japan houses now a days put 'X-mas tree' despite have nothing to do with it. It sells dude, if Hanukkah or whatever other holiday become know globally you can bet they will get skins out of it. If not take for example the Octoberfest, the St. Patrick, Harrowing and the Chinese new year skin lines. All of them are "holidays" of very small regins of the globe but are known globally and thus they have skin lines.
Want more examples? See the sports line section, we have for the Soccer World Cup adn the Olympics (the 2 most seen events) and we have none for the Basketball Finals or the Tennis open since they are not that famous or globally recognized.