You could say that one time making the wcf was a fluke occurrence. After that, the last two seasons they lost twice without much fuss. He was obviously not good enough to push them further then before. The stats are generally skewered towards offensive output in this era, that is the reasons he can be painted as being better then he is. He isn't a good defender neither does he have that much room to improve there and he doesn't have the personnel good enough to cover for him in that department ( dunno who could be brought in to help

).
I just don't see him being the main cog in a championship winning team, maybe even not the robin on such a team.
How can he be better then Jamal Murray, did you even watch this year's playoffs. Murray was scoring left and right and especially when the games were being close, Murray would score to keep Denver ship steady. His defense wasn't pristine, but he wasn't blown by on a regular basis. Maybe Atlanta lacks the second guy for the kinda of combo Denver runs, could be that.
I have issues with stats in this era, almost every no. 1 option on a team will get "their share" just due to the sheer volume of scoring and the way the game is played. It could be said that stats in this era do not reveal the full picture. Hell, you can call that a blasphemous view, but that is my subjective feel here.