It's like when people say "more unique." Impossible! "Unique" is an absolute state, it is not subject to gradation.
That's one of my pet peeves. If we water down the word "unique", there is no other single word to replace it, just the phrase "one of a kind".
My other current pet peeve is using "literally" to mean, well, not literally. That one gives me a (figurative) headache!