"Nice" people are almost never as kind as they think they are. Generally speaking, they don't like themselves enough to be their own person, so they contort themselves into shapes they believe others want to see.

I think most people can usually sense this lack of genuine behavior, which makes the response to the average "nice" person rather lackluster (there are exceptions).

The result is often that the "nice" person feels as though they have sacrificed themselves to make you happy & becomes quietly resentful of your lack of appreciation. The reality is that they are just manipulative, power/status hungry, & angry people. I think this is basically the core of all self proclaimed "altruists."

"Nice" people don't have enough spine to tell the truth. What the world really needs is people who deal only in what is real.