I think fans opinion of Dembele diverges so much because of a growing frustration that he has not hit the heights which his obvious talent demands. The stick used to beat him with is that he is under-performing compared to where he should be, and honestly I don't think that is valid viewpoint. He has more than likely gone past the point where he'll improve enough for the RMs or Barca's of this world. I'm pretty sure that ship has sailed but that does not make him a bad player by any means.
The lazy analysis trotted out that he doesn't release the ball is almost tabloid journalistic in its blinkered view of his contribution on the pitch. That is only one aspect of his play of which an opposite viewpoint could be taken that he retains possession well. The truth is as always somewhere in between. Do I think he should move the ball quicker on occasion? Yes, but not every occasion. His inclination is to keep possession by default, and when put under pressure that is his fall-back mindset. It is a mindset that has be trained into him IMO since his move back into CM at Fulham and Spurs. AVB had a big part to play in that I believe, but you can see this season that if when he is moved further forward (to his Alkmaar position) a lot of the hesitation has disappeared.
I'm too lazy to check but I'm pretty sure Dembele got some good scores in the match ratings for his cameos and starts up until that last outing. He had a stinker then but everybody else did that day too if I recall. Whereas Paulinho is a nothing player for me. Does nothing well that I can see and slows our play down far worse than Dembele ever did. On on top of that Paulie plays like a coward and passes responsibility (literally) at the earliest opportunity. I would play Dembele 10 times out of 10 over Paulinho.