People liked Macklemore because his stuff was inoffensive and mass-market tuned. Pop-rap. Not a bad thing in itself, but through it's very nature more people can listen to it and like it, and then some take it too far and say he's the only one with something to say, when in reality it's really he was rapping what they wanted to hear.
The difference between Macklemore and Tupac, Dre, Snoop, Em, Biggie is their songs are personal. You'll probably hear a thrift shop cover years from now, but nobody is going to cover any of the hip hop songs because it doesn't make sense why a 20-something starlet is talking about their mom stealing their medication to high off of or seeing their cousin blown away by a cop. People from the same background can appreciate the songs more because it's catharsis for what they have to live through and feel like someone else is going through it too. It's a musical documentary, not a star vehicle.
Anyone can still write on and grade the songs, though, because even if it's real, you have to put it together in a skillful and clever way. I can't really grade Tupac's story that he tells, persay, but I can sure pick apart some clever beat switches and rhymes and half-rhymes and explain why they're cool. That's reviewing the technical side of it. Then have the hip hop mags write and talk about the emotional side of it. Write to your intended audience
