I feel like the term 'bust' is thrown around too generously. Can you really call players drafted after the first round a bust, when the percentages of making the NHL for players taken after the first round being very small? I would call them a 'miss'.
A good team needs to hit on those picks, so the Sabres getting 1 or 2 NHL players after their second round is the mark of a good draft and scouting.
OK, so Poltapov and Leinonen eventually may fall near that 'bust' criteria being second rounders, but I would also look at the totality of that draft year and depending on what they did hit on in the later rounds, put them in a 'miss' category.