That's not naivety at all. You chose to ignore the "if" that I wrote in that sentence for that very reason. I will repeat it for you, as needed:
"IF all of the involved parties are aware it's a clone and not an original Pokémon received legitimately, and none of them care, then that's their business."
To be clear, I don't think you're disagreeing with me, or if you are, I'd suggest reading closer. Cloning is an unintended, unsanctioned, and abused glitch, unequivocally. But people are going to use it anyway, frequently under the (wrong) justification of "well, it's in the game, so it's not illegal." And so when they choose to make use of that glitch, so long as all involved parties - themselves, or themselves and a trade parter - are aware of the mechanics involved, then that's their business. To be even more clear, just in case I need to be so, cloning Pokémon and then giving them to people without informing the recipient of the Pokémon's cloned origins is absolutely wrong.