The real Saint Nick had a genuine concern for those who were “naughty”, but not in the sense that we use the word today… he cared for those who had “naught” (though he also had a penchant for slapping heretics, who were “naughty” by a more contemporary definition). Check out the etymology of this word, courtesy of dictionary.com:
Late 14c., naugti “needy, having nothing,” from O.E. nawiht (see naught). Sense of “wicked, evil, morally wrong” is attested from 1520s. The more tame main modern sense of “disobedient” (especially of children) is attested from 1630s. A woman of bad character c.1530-1750 might be called a naughty pack.
Similarly, the word “nice didn’t always mean what we think it means…
Late 13c., “foolish, stupid, senseless,” from O.Fr. nice “silly, foolish,” from L. nescius “ignorant,” lit. “not-knowing,” from ne- “not” (see un-) + stem of scire “to know.” “The sense development has been extraordinary, even for an adj.” [Weekley] — from “timid” (pre-1300);to “fussy, fastidious” (late 14c.); to “dainty, delicate” (c.1400); to “precise, careful” (1500s, preserved in such terms as a nice distinction and nice and early); to “agreeable, delightful” (1769); to “kind, thoughtful” (1830). In 16c.-17c. it is often difficult to determine exactly what is meant when a writer uses this word. By 1926, it was pronounced “too great a favorite with the ladies, who have charmed out of it all its individuality and converted it into a mere diffuser of vague and mild agreeableness.” [Fowler]