They are making it seem like this was shocking news. The man has had an amazing career, spanning numerous decades, he is well regarded in his field, and he is nearly 80 years old... He will be missed, but this isn't exactly Earth shattering.
Seems like the news and media are blindsided by his announcement.
ETA: Sorry that I wasn't clear.. he is retiring at the end of the season, but the way it is being reported, it seems way bigger than that.