i think people dislike the lion king for the same reason they dont like pooh- the market was and in many ways still is, saturated. i think the lion king is one of the best films disney has ever created,
personally, if a film doesnt live up to its hype who cares. its one persons dissapointment, as i have said in other threads i love a good story and excellent animation and i think the lion king has all of those things in spades.
labelling something as 'overrated' doesnt really count for anything
1) the lion king
2) the little mermaid
3) so close to 2 it isnt funny- beauty and the beast
4) aladdin- great movie, but dated due to the comic references