There is no such thing as an overrated product; just an abundance of narrow minded, knowledge-lacking consumers.
A rating is simply how a person compares said product to another. Those people who bash a product that is "overrated" usually say: A)"It is bad for the price" (anyone heard people on headfi complaining about Beats? Well, usually complaining about the owners of those headphones...) or B) "A product has become so popular in a certain price range and therefore just because it is popular then it must be overrated" (I saw a post somewhere saying 'Are m50s overrated now?').
I don't believe in an overrated product. I just believe that some people, while may be ignorant and lacking in knowledge, are just giving their honest opinion about how they feel about a particular product compared to something else, and I see no fault in that. I don't see the need for someone being arrogant about his higher knowledge of something compared to someone else and telling them their product is sh*t. I would rather just enjoy my own purchases rather than worrying about what other's think of their's, and your's.
Just my thoughts on something I have observed here at Head-fi.org.
(Note: Justin Bieber still sucks despite opinions.)