I don't disagree with you there. These days (many, many, many years now), you don't get a sniff at the Selke if you aren't also producing at least beyond a certain threshold offensively. I guess the argument is that you are a forward, you should produce points and if you aren't doing that, it's part of your game that is lacking.....Selke isn't for best defensive player, it's for best defensive forward, so offense is part of it....i guess that's the argument and I don't disagree, but the guys winning the award aren't necessarily the best defensive forwards.....for example, I would have voted Zetterberg over Datsyuk in some of those years.
The other angle though, forwards not playing PK aren't necessarily not great defensive players. A lot of coaches won't put his star player (forward) on the PK because the reward doesn't outweigh the risk. Greater chance of injury, but also, player can't really play 30 min a night like a D, so those minutes are taken away from other areas. I think the view is that PK is really a skill that you can teach and with hard work player B can fill that spot just as well as player A, so why put player A in that spot. I'm not making an argument here about why someone should be considered for Selke even if not playing PK, just suggesting this is a reasonable view.
Actually, here's something when it comes to PK...being really good at it doesn't necessarily make you a great defensive player either. It can just be a skill that some guys excel at. I watched more PIT games than normal down the stretch due to what was happening with the games...so lots of PIT, WSH and DET, etc. Rust seems to be one of the top choices on PK and he's pretty good at it....but on balance he seems horrible at defense. This is purely just from watching, not looking at any stats though. One last thing on PK....has anyone done a deep dive to see who plays PK more.....centres or wingers? Positioning in the D zone during PK would actually seem more natural for a winger, but I'm guessing stats don't show that and certainly not something I'd defer to wingers on.....my son is 14 and plays centre and when his team is on PK, he'll start with one of his wingers, they'd never put his two wingers out instead and I'll admit, when they roll through the lines and put two wingers out I cringe......face-offs is a big part of it too though.
Long story short, I agree with you, there are guys that play really great D that will never get credit for it and likely better than Selke winners simply because they aren't producing enough offense to get themselves noticed.