I think you're not seeing the bigger picture from the perspective of Blizzard. Yes it's because he's a public figure, because he represents the face of the game for so many people and that he's a role model just as many.
Not only was he displaying immature behavior but he was also inciting others to do the same. That's leeway you just don't have as a professional. Because he's getting paid to play this game he HAS to display more maturity than random Joe next door.
In my opinion just being suspended from comp and season 0 would have been enough but they wanted to send a clear message. Regardless of whether we think it's fair or not because they absolutely can't have this be propagated and seen as acceptable.
I doubt they will do this but it;s always easier to reduce a sentence then to increase it after it's been given. But something like this needed to be done.
Again, the game is young and so are all the pros. Mistakes will be made, lots of learning needs to happen in the scene right now, lots of maturity needs to be developed at the top level.