Honestly, it's not clear exactly why either DD or Bloom were fired, because as has been said a zillion times, they both seemed to be doing exactly what they were hired to do. Yes Bloom's W-L record the last 2 years had to do with it, but if Henry was so keen on winning why didn't he spend a bit more?
The only thing we know is that the same guy fired them both, the same guy who has canned 3 CBO's in a row after 4 years, the same guy who's mostly responsible for all these stories about people being leery of the Sox CBO job.