There's probably a combination of reasons, but there's no doubt in my mind that a segment of the voters chose McGlynn over JBA because they wanted to nominate a Scottish manager rather than some upstart foreigner trying to modernise the Scottish game.
You don't need to go too far back in the season to find all the criticism doled out at the start of our project.
McInnes will win it anyway, and JBA will be on the sportswriters' nominations no doubt.