I don't see any problem with getting someone a pet for Christmas, as long as it is a planned for thing, and not just a total unexpected surprise. Unless you know exactly what the person is looking for, and know for sure that they want the puppy or kitten (or anykind of pet); then I certainly think that thisis a decision that is best made by the person who wants the pet.
I think that this would normally be how it is done, and the person who is getting the pet would pick it out, even if it were being given to them as a surprise.
You see pets advertised a month orso after the holidays, just because someone thought that their spouse, child, or parent would just love the cute cat or dog.
Now, they are tired of trying to housetrain it, and all the slippers in the house have been shredded, and they just want the pet GONE !
Even if it is not at Christmas, or any other holiday; I think that people should only get a pet when they pick it out for themselves, by and large.