It's really quite a fascinating point. Interesting dynamics of these microorganisms....though i'm not sure they adapt into every environment...like the baked sweets...and the fruit juices ok sure.....but like you pose the question,
have you ever heard of sugar going bad?
I have not.
Though I can remember the brown sugar becoming all clumped and hard like chunks when it was exposed to air for awhile. Not sure if the same would hold true with white sugar.
thanks for comment.