Pau is definitely not a force right now. He is being used strangely by the Lakers and on top of that, his confidence seems completely shot right now. He's missing wide open shots, fumbling easy passes, and basically just seems nervous whenever he has the ball out there.
He is really no longer featured in the post and he's taking 5 shots a game from the 16-23 foot range, more than double his career average. To contrast, Kobe's bread and butter is the 16-23 foot fadeaway and he is only shooting 4 of them a game this year (about half his career average). Not much of a surprise that their percentages are going in opposite directions. Still, Pau is 7 feet tall and is more versatile than just about anyone his size. His 42% fg% is awful for a big man but it's passable for a shooting guard, which is essentially what he is these days.
I think the whole reason people tend to back Pau in a lot of these arguments is that he is instantly scapegoated for anything that goes wrong with the Lakers even though he wasn't the one getting all of the credit when things were going well. Also, during that 2011 playoffs, everyone ripped Pau for being 7 points off his average but no one seemed to notice that Kobe was ALSO 7 points off his average. Then in the 2012 playoffs, Pau was down again but Kobe was the one that was invisible late in games and almost singlehandedly blew a few very winnable games down the stretch but again, all eyes on Pau.