Honestly you can't even cite Eminem as a reason for him not being overrated, Dre didn't really do shit. Dre produced literally 3/15 songs on Em's first album. So really it was just Dre's name behind the shit. and the Songs he produced (which were the singles of course) Aren't even half as good as the rest of the album.
and you can't say "oh well lets throw some other record exects in there then cause they have more flops" Bigger labels have a bigger umbrella. Theres literally over 200 artists signed to Universal, of course there's gonna collectively be more flops than Dre's label, but the difference is Dre is running the label himself, with major distribution. His umbrella is way smaller so it would be easier for him to prevent a flop. now if you go by artist-owned labels then Aftermath is probably the worst, along with Shady and Rocafella (don't say the obvious "but but kanye", because theres still Osheeno & Sparks and numerous other flops)
How can you honestly say Dre didn't really do shit? The guy fucking put Eminem on. I mean, this whole damn tread is about Dre's abilities/direction as a executive of a label right? If that's the case, signing Eminem (taking a chance on a white rapper at the time), producing his singles which perpetuated into his mainstream popularity, and putting him on with other rappers (Xzibit, Snoop, Nate Dogg) does not constitute the label of overrated. Again, he co-signed w/ Em to put on 50. He moved Game to G-Unit. He co-signed Kendrick. These are all executive decision that keeps Aftermath still relevant.
And as I stated earlier, every label from Bad Boys, Rocafella, Ruff Riders, and Cash Money all had their share of hits and miss. You can't just single out Aftermath. Now you're entitled to your opinion but I beg to differ with Aftermath being labeled the worst as their artist put out more quality material compared to other labels.