I don't believe the highlighted portion is a fair comment. You and I can agree on this, sure, but many others disagreed with any criticism levelled at Slaf at several points this season. It made for an insufferable discussion. It's been three years of this and ongoing.
Very few comments or commentators indicated that Slaf was done with his development. Seems like you're chasing shadows.
Incidentally, a player's not being a finished product also means he could simply not improve. Improvement isn't guaranteed. Kostitsysn, Galchenyuk, and others never improved.
You're mistaken here thinking commentary is the same as hate. We're in a dialogue with other fans here. We are not in a dialogue with the organization or the players themselves. How a commentators write about a player has to do about the ongoing dialectic rather than some absolute barometer of their impression of the player. There are precious few words written about Suzuki relative to his contribution because most people are aligned on him: he's great. Slafkovsky doesn't have such alignment because he's inscrutable, inconsistent, and (some will say) overrated or underrated. He's up for debate.
Shots on goal are important and it's good that he's shooting on goal, in my book there is no higher praise than comparing a big powerful forward to a sasquatch but if you think we should get his name tattooed on our foreheads to prove that we're happy with his performance in playoff game 3 I invite you to do it first.
To me it's interested to figure out just how valuable is "the little stuff" versus the more easily noticeable stuff?
Lehkonen is an example of a player who did the little stuff well but was rarely rewarded when he was here. He was traded away rather unceremoniously. You need to do the big stuff too. Slaf is inconsistent with both. Maybe he'll turn the corner, hopefully he does (hopefully he has).