There were plenty of good obvious options, it seems like Hunter wanted to show everyone that he's the smartest guy in the room and go for something out of left field.
If we swung and missed on a Benson/Kyrou or one of the regular guys ranked in the low 30s, no one would be upset. 31 is too strong of a pick to get weird with.
You are overvaluing the 31st pick. Guys drafted from 25-30 pretty much become something of value to you NHL team like 30% of the time. If Korshkov becomes a top 9 player, which he still has the chance to, that's a hit regardless of who was taken after him. Korshkov also got injured twice, which sure as hell didn't help his development. By your same standards SDA and Hollowell were essentially the smartest guy in the room picks. Korshkov was a reach.
Your logic basically amounts to, it is fine to bust if you just draft with consensus. At the end of the day, results are all that matter. If you draft a consensus bust, it is just as bad as drafting a reach bust. Just look at the Oilers, Puljujarvi, Yakupov, and MPS were all consensus guys in their range, and those misses are crippling. Maybe if you do something crazy in the top 10. But once you get out of day one of the draft, a miss is a miss.
If Korshkov somehow turns into a decent 3rd line winger, which is still possible, that is a better pick than you usually get in the 31-35 range. Yeah, its not a Debrincat or an Aho, but those are extreme exceptions. The list of guys drafted in that range tends to be filled with more guys like TJ Brennen, Tomas Kana, Chris Bigras, Landon Ferraro and Chris Bigras. I wasn't a huge fan of the Korshkov pick, but, if he just turns into a competent third liner for 300 to 400 NHL games, that is beating the expected value of that pick.