Tkachuk?
The question is a bit loaded though, given the context of that timeframe.
2012 we took Ceci, a Defenceman, with our 1st pick. And that draft class SUCKED, so the chances of finding a top-6 F in that year past the 1st round was slim. We correctly swung for the fences with a boom-or-bust guy in Jarrod Maidens, but injuries derailed that career (which was the main "bust" risk)
2013 was the Lazar draft, so fair call on that one - that was a bad pick, period. No 2nd rounder in that draft though, and we used our 3rd rounder on a goalie (Hogberg). 4th-7th rounders rarely become top-6 players.
2014 - no 1st round pick, used our 2nd and 3rd rounders on defencemen. Defenceman can't also be top-6 forwards. We spent the 40th overall pick on Englund, who sucks, but man... look at that draft year. There's arguably only 2 players taken after Englund in the entire draft who are a top-6 forward: Brayden Point (3rd round, 79th overall), and Viktor Arvidsson (4th round, 112th overall). It's not like we "just barely missed" anyone. That draft class had no depth, and we had no early picks. Even if we'd taken the next best defenceman instead of Englund, that would have been... Brandon Montour, at 55th overall, 15 picks after Englund?
2015 - still a bit of a wait and see. We used our top pick on a defenceman, Chabot, who I don't think literally anyone will ever complain about. Potential annual all-star. Second 1st rounder was White - probably ends up our 2nd line C sooner than later, clearly has the talent to do so. But he's just 22 years old. Give it time. Other than that, Gagné was a bust, Chlapik seems to be a depth guy.
2016-18 drafts = too soon to tell.
So... I see some forward busts in this group for sure, but looking at the context, the only really BAD pick, like egregiously bad, is Lazar. The rest is us prioritizing the blueline, and in some years lacking high picks because we traded them away. And then us still waiting to see if the new generation pans out (Brown, Batherson, Formenton)