Maybe because their efficiency ratings and advanced stats aren't close?
Kyrie has hit career lows in nearly all statistical categories and Dion isn't even in the same ballpark.
No one is saying KI doesn't need to bounce back this season but after 2 years, Dion is a completely average 2 guard and yet everyone defends him tooth and nail. Why? Because he's more likable?
People reference his age but perimeter players don't have a history of developing slowly or struggling early in their careers at the NBA level. The only guys that even remotely fall in to that category are ones who never got a chance at that age or were playing with players that didn't afford them offensive opportunities.