Hybrid Theory especially is overrated because it's what catapulted LP into success. Meteora, being the sophomore album, kind of rode Hybrid Theory's coattails. Anything after that is way less well known, and therefore you'll see many more opinions on Hybrid Theory and Meteora than you would their other albums. If you look purely at that, I think it would be factually accurate to call those two albums "overrated" when contrasted with the base knowledge of the band's later work by the general music listening population. It's not necessarily a problem of being overrated, overexposed is a more accurate term. However, personally, among the people who do have exposure to more of the band's work as wholes and not random single releases beyond the first two albums? Yeah, totally overrated.