Why doesn't the achievement Blowin' in the wind update?
I keep breaking objects with Whirlwind but alas nothing happens on the count.
Could the objects be specific or is it only updated once or day?
Does anyone have some experience with it?
I have noticed this and it only appears to have with certain achievements. The achievement itself is updating, but your client's achievement screen does not update in real time for certain achievements.
Specific examples that I have found so far are achievements similar to the one you've mentioned with a counter that exceeds 10, for example the achievement to break Ashes [general], kill 100 enemies without reaching full spirit [monk], gold picked up [general], etc.
However achievements with lower counters (listen to Shen say 6 things before breaking his barrel) do appear to update in real time. I am unsure of the cause of this issue but once you reach the achievement threshold you will gain the achievement, and the status of your achievement will update at various points. From my testing it appears to be when you join/leave a game and when you change zone.