I just find it strange that they would be put together. It’s not uncommon for a species to attack their own species when they look different. Look at the way black crows will attack and kill albino crows that nature every now and then throws out.

I think they just didn’t want to bother having to clean another cage.

Here’s an interesting article on how white tigers are almost certainly a product of inbreeding within the zoo:

http://www.felinest.com/white-tigers-are-not-natural/

If what it says about genetic mutations perhaps the tigers did the white tiger a favor… sad to say that though.