Because the ONLY argument we would have to kill and remove them at all, is if they were "man-made". And personally, whether or not it is a "known fact" that they were placed there by man. If they were transported buy nature.....ie, flooding waterfowl etc? Then they are part of the "natural" process....they "belong" there. And to remove them would go against everything that the protectionists killing off species are supposed to be for. It's not a matter of which one was there 1st. Nobody knows how the yellowstone cutthroat got there to begin with. Or whether or not they displaced or outbred another bloodlines as well. It's all speculation.....we just like to claim the favorite that WE know to have been there 1st as the most important and only valid species.
Unless we are only really just picking favorites?