Justification for white tigers
I had this conversation years ago with the late, great Uly Seal, the academic who essentially started SSP's, beginning with tigers.
In a well-run zoo, white tigers do not TAKE-UP space, they CREATE space. What do I mean? Admissions go up so much with the display of the white color variety, it helps maintain many of the other breeding programs, and,for that matter, the zoo itself. This is especially important for private zoos like Wildlife World or Lowrey Park, which are not on the public teat, and must survive on admissions and donations. These zoos would have significantly less funds without the display of the whites.
I find it fascinating, and a real peek into AZA politics, to see that white alligators were not banned by them at the same time, an even bigger attraction in terms of increased revenue