http://www.etymonlin...x.php?term=nice
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]
"I am sure," cried Catherine, "I did not mean to say anything wrong; but it is a nice book, and why should I not call it so?" "Very true," said Henry, "and this is a very nice day, and we are taking a very nice walk; and you are two very nice young ladies. Oh! It is a very nice word indeed! It does for everything." [Jane Austen, "Northanger Abbey"]
Thus my original post;
The origin of the word means to be without thought or thinking. In a way you could think of it as being non-threatening to someone because you were retarded.
Since our society has repudiated Christ, we have left behind the core societal value of truth. It has been replaced with a core societal value of comfort. The worst crime you can commit today is to make someone feel bad.
The Christian is to tell the truth in love.
Even in Christian circles many people have opted for the "warm fuzzy puppy" form of communication where everyone gushes meaningless drivel like a Hollywood starlet or a presidential candidate attempting to make everyone feel good.
Biblical love is just simple self-sacrifice. Often what passes for "Christian love" today is gooey emotional self-stimulating sentimentality.
Today when people ask others to be nice, they are often asking others to sustain the comfort of their self-delusions.