Calm down children.
McGregor isn't overrated, but it's undeniable that he was given the opportunity to win two titles under questionable circumstances. He went 1-1 against Nate Diaz and then got a title shot. This was after never defending the title at 145.
This would be the equivalent of Anderson beating Rich Franklin, then getting booked to fight Chuck Liddell. Then, Chuck gets injured, so instead he fights and loses to Keith Jardine at heavyweight. After that he would get an immediate rematch, win, and then fight Rampage for the LHW title.
No one would be praising this as some miraculous feat. It's for sure impressive, but we need to relax and look how we got here.