I don't know a great deal about genetics. I am certain there are people on this site with "phd" at the end of their name that will blow me out of the water. However, from what I understand an albino is merely a mutation. Most animals we know have evolved over millions of years to be what they are today. OK, so some guy called De Vries reckoned that evolution is a product of mutations. But, anyway, back to my point. In the wild, you will probably see the same number of albinos as you do in captivity.... until ... you start getting them in captivity, that is to say that getting your first albino is a matter of chance and probably the same chance as a wild one. But as the wild ones are not following their evolutionary path chances are they will not survive as well as the captive ones. And there is probably less in breeding in the wild so maybe their chances are lower.
Once you have an albino you can then work out which animals will carry the gene (I remember "splits" as we used to call them in the bird world). Even though they look normal you can still selectively breed them. So maybe the reason that these things happen overseas is that they are kept in much less natural conditions than in Australia, there is more inbreeding overseas (done on purpose), there are no wild caught specimens and there are simply more of them in captivity overseas. All that coupled with the luck of getting the 1st one.
In years to come, as our hobby matures, we will have a lot more of these type of animals. Just look at Cockatiels and Princess parrots and what they have come up with in the last 30 years. And now all these variegated species have been taken out of the licencing system cause its pretty hard to take a harlequin budgie from the wild. And a white cockatiel was a lot more expensive in 1979 than it is today!!
JMH (unqualified) O