That's a way to offend someone instead of saying things like "Fuck you" or somethinglike that.
It is mostly used by moonwalkers (Michael Jackson Fans).
Something is outside of the general trend. There are people who don't understand the usefulness of generalizations so they always have this as a comeback. Mostly when they are butthurt about the truth.
"Modern/Western women are bad at cooking."
"Not all of them! My sister's husband's girlfriend makes nice sandwiches!"
Short for: "It takes all kinds". Takes all kinds is a way of saying "I don't know, that person is weird, but it takes all kinds of people to run the world, even if those people are weirdos."