#3 No Faith?

While Nakamura was positioned as a world-class talent down in NXT, that reputation doesn't seem to have followed him up to the main roster.
Obviously, his thousands upon thousands of fans are always going to think he's one of the best in-ring performers in the world, but it doesn't feel like the WWE themselves possess the same mentality.
Cody Rhodes' uncle is a WWE Hall of Famer. More details HERE.
Since debuting on the SmackDown Live after WrestleMania 33, Nakamura has been involved in several high profile world title matches against Jinder Mahal and Styles: and he's lost all of them. We can understand him losing to Styles on some level, but the Mahal defeats?
The company didn't believe in him then, and if they weren't confident enough to give him the big win at Mania, then maybe it just isn't meant to be.