This is a fair point and one that doesn't get made enough.
People have always, always wanted Pogba to be more than he is. When he plays high up they expect him to be Zidane. When he plays deep they expect him to be Viera.
When Pogba signed I thought he could maybe evolve into a Yaya Toure type attacking player. Its fair to say he showed ample evidence of being able to play that way when Ole first took over. With his poise on the ball, passing, pace and power he's very hard to defend against in advanced areas. However, he is not a dynamo and expecting him to run about like Rooney is like expecting Maguire to sprint like Ferdinand.
Pogba and Bruno are different players, with different strengths. It just so happens that as #10 Bruno's game compliments/makes up for the weaknesses in our team more than Pogba's. That's nobody's fault per se. Its just how things have worked out with the way our squad has been put together.