You and I clearly have a broader sense of what are "legitimate" names than others might
Obviously you and I feel, if I may say, that legitimacy is largely conferred by the namer, regardless of others' opinions, though I know I don't, and I presume you don't, choose names that others consider "illegitimate" just to piss them off. ;p
I don't intend to speak for anyone else, including you, when I say that, to me, Dakota and Cheyenne are as legitimate as Saxon (tribe name) and Paris (place name). Nor do I intend to start an argument (though I don't see why it's such a big deal that it could start one).