My question would be what assets does he bring to a PP? He's not a good passer, not a patient player who thinks a step ahead, doesn't have a accurate shot...what does Brendan Smith do well to deserve significant PP time? I agree his "nature" is to think offense...he just doesn't have the skill to make things happen.
He's plenty good at passing. He's also very quick in the offensive zone and has some creativity up his sleeve, more so than anyone not named Kronwall. I'm also not seeing a shot that is any less accurate that pretty much anyone else on the team. But there is little point in pointing this out to you when you had your mind made up about Smith eons ago.
The more important point you seem to be overlooking is that getting consistent PP time could help his development. Powerplay time by its very nature is in-game practice for your offensive skills. There's also no telling what it could do for his confidence, and how that could translate to the rest of his game at even strength.
I'll never forget one of the last games Kyle Quincey played for the Wings before he was waived. It was either a blow-out and he was seeing PP time, or there was a shift of extended pressure in the offensive zone while he was out there. Either way, the puck came to him a few times while he was at the point, and he got off some of the most pathetic shots I've ever seen from an NHL defenseman. It was so bad it was comical. The puck looked like it was moving in slow motion. By the next year, he was on the top PP unit in LA alongside Doughty putting up nearly 40 points.
Ergo, I really don't understand why some think its a ludicrous argument to say that Smith, under the right circumstances, could be a better player than what he is now. Its not like he's Brian Lashoff - there are flashes of brilliance that you can see almost nightly. I don't think anyone is saying that Smith looks like some offensive dynamo at even strength, but its silly not to give him time to become comfortable on the powerplay and see what he does with it. If he does nothing, then fine. Let's dump him. But I'm reluctant to judge him in such a hard and fast way until we've explored some of the most reasonable routes to help him take his game to the next level.