Misaligned teeth are not the worst problem IMHO. The fact teeth of most of the humans decay in less than a lifetime and this is considered normal feels much more weird to me.
Reasons being: certain parts of the dental periphery are more vulnerable since they are supposed to be covered by gums or neighboring teeth.
My dentists keep saying that our teeth are highly specialized in every meaning of the word, and every deviation from the beaten path is heavily penalized with decay and a number of other conditions.
:(