Henderson is only 21, hes got plenty of time to grow and get better as a player, would be different if he was 27/28 and was performing bad then I could see why people complain.
I think he should be played more in the middle, when watching him he looks like he wants to keep the ball and keep possesion simple passing, and he puts in a good shift plenty of running. He also looks like one of the fastest players in the team when he at top speed, would be good to see him bursting from midfield to help support the strikers a bit like Gerrard, but still has plenty of time to learn this.
The only bad thing I have to say about him at times is that he needs to be more rough in tackles and hassle more players on the ball, maybe the reason he isnt played in centre midfield as much.
But still a good player for the future and played well today, should also take our corners looks a decent crosser too.