Directly is a bit loose term, I agree. I meant it like in a scenario where I hear a song and I like it, either over the radio or TV or Youtube. If someone recommends it doesn't mean I became a fake fan because of the recommendation. But when I read reviews and praises that claim "legendary", "cult" and "epic" virtues of a band and I go for it and train myself to like their music without any proper critical filter, I'd say I've been hoarded to join the fan herd.
Reason for this is the need to belong, to garnish one self with "coolness" (socially acceptable behavioral patterns). You can read more about this animal behavior in Behavioral Psychology and the works of Gabriel Tarde (Imitation).
Becoming a fan for any other reason than personally preferring the musical aesthetics because of who we are (and have become) as a person in life, I'd say you are one of the many who help the band become overrated. "You" as in imaginary you. We've all done this, it comes natural to us with our gregarious instincts.
To me personally The Beatles come #1 in being overrated.