Personally I don't think white tigers are all that beautiful given the long history of hybridization and inbreeding that is behind these mutated cats. A story that doesn't speak very well about (the history of) zoos either. Also I don't think white tigers, at least compared to normal tigers, have much and certainly not the same conservation or educational value. I don't like to see these all that much and would prefer to not see these propagated (as Mondo Verde still does).
I also believe that zoo organizations like EAZA and AZA aren't too happy about the white tiger thing and generally don't look well upon members breeding these. But Mondo Verde is not an EAZA member so they can probably get away with it.
@KevinB Oh, I had no idea about this. I'm more of a bird person and never really looked into tigers, just appreciated them for what they look like basically.
I just know my closest zoo(Parken Zoo in Sweden) had white tigers when I was a kid.