I'm not going to fault BG or any other teams GM for failing to sign a college free agent as long as there's a documented effort to get him signed ... and there was. They have all the leverage while NHL teams have a max they can offer in terms of AAV, unless they are willing to throw in huge bonuses where a projected bottom six player like McBain does not have precedent.
McBain was likely told he would be playing a year in the AHL and seeing how he would needed to beat Hartman/JEE/Gaudreau/Dewar, it made sense for a new prospect to develop. And also IMO is very fair. He wanted to skip that and go straight to the league and Arizona, a bottom NHL team with tons of roster openings, gave him that chance and a full NHL paycheck.
He probably also saw how our center competition could look over the next years, with Rossi and similar player of his type in Bankier, he would have a harder time. So he made full use of his leverage. Good on him - part of the business and a part everyone has to accept.
With the historical talk of the Russian factor fear when it comes to drafting players, I have always found it funny there isn't at least a inkling of that fear when it comes to drafting college-bound prospects. There isn't that fear of home sickness with college players but they arguably have the most leverage of any other type of prospect as their rights expire and they have the ability to become free agents if they so feel like.