Basically think of the Platy as a combo of two copies of a lesser complex mutation just like mystic potion (mystic and mojave), crystal (special and mojave), or one of the blue eyed leucistic combos like mocha and Vin Russo. The only really odd thing about the Platy is that one of the alleles of the lesser complex in that combo is so subtle its reported to look completely normal. Because it looks normal it's been hard to pin down a good name for but I've heard "hidden", "platy sib", and "dilute". I guess it does get a little weirder because apparently even the homozygous hidden looks normal. But try to think of it as just a really subtle member of the lesser complex and you see why a combo like Platy produces only hidden and lessers when bred to a normal and no Platy and why a lesser can't carry hidden without being a Platy.