What I don't like about that answer is that humanoids are supposed to have free will. We would not say "Moradin is Lawful Good and instilled Law and Goodmess in dwarves. Therefore, chaotic and or evil dwarves are extremely rare. You should always be able to trust dwarves are being honest and fair with you. It goes against their creation to not be."
I mean, we can I guess. All elves are chaotic good, all halflings lawful good, etc. That's just the way their Gods made them. They can't not be, and those who are are outliers, as rare as Drizzt would be. Dalamar is as opposite to his kind as Drizzt is. But generally, we give elves and dwarves a wide array of alignments we say goblins and orcs can have, but rarely do.