This isn't making much sense to me. Guys like Pageau and Hoffman are objectively good players while Smith hasn't done zilch. I guess you could apply your argument to guys like Ryan and Brassard who are both inconsistent(Ryan especially), but whether a player is good or bad isn't subjective in general. Putting Karlsson in this conversation shows how ridiculous your argument is.
You think Karlsson has had a good yr? Maybe it's because he has had so many better seasons that I expected more from him this yr but this board, you included has mentioned this dozens of times this yr.
On Smith, there are things that he does that coaches love but clearly some fans don't appreciate. He is strong in the faceoff circle which normally takes young players a few yrs to get good at. He is known for being very good defensively which is why GB has him out there against other team's best line. He has basically taken over Pageau's defensive role on the 3rd line since Pageau is now the defacto 2nd line centre. Smith has good size & plays with an edge that a lot teams covet & want going into the playoffs.
Having said that though, next yr IMO would be the best time to move him to allow White to take over his role, he seems like he would make a good defensive centre with a little more offence.