I think part of the reason for the reaction isn't the quality of his games, but his role in them. He's the "Creative Director" and Lead Writer, he focuses more on the storytelling side of things, directing actors, scenes and so on. In Naughty Dog, the directorial roles are even divided as Game Director / Creative Director, indicating the separation.
He's an excellent director and writer, but when you contrast him with Miyamoto, Miyazaki and Kojima, he's being praised for a very different set of skills. They're not worth less, but they're different. I wouldn't put Austin Wintory and Olivier Deriviere alongside Kojima or Miyazaki, even though I think they're brilliant composers and greatly value music in games.
I'm sure as a director he also has a ton of input in game design, but even then, the game design part of Naughty Dog's games is largely derivative, even if superbly executed. Their expertise is impeccable cinematic execution, not genre defining game design. I wouldn't put the Game Directors of his games alongside Kojima and Miyamoto, so I definitely wouldn't put him there either.
And I say this as someone who likes The Last of Us more than any Kojima or Miyamoto game I've played, so I genuinely mean nothing bad by it. It's a different category, not an inferior one. Unless A Link to the Past counts as "a Miyamoto game", in which case, that one is something else.
There's also the fact that Miyazaki has been considered one of the greatest directors in the industry since before Druckmann's directorial debut, which justifies some of the puzzled reactions.
