The reason Savard was fired is that Bowman is the de facto GM and didn't think Savard was the right man for the job.
The reason that I think Bowman is the de facto GM is because it would be both antithetical and foolish for the Hawks to hire the best head coach in the history of the NHL as "Senior Advisor, Hockey Operations" and then fire the head coach over his objection.
Furthermore, Bowman's career has earned him the privilege to impose conditions on his employment. Given that he nearly took over as president of the Maple Leafs after an incredible career with the Red Wings, it would seem unlikely that Bowman would be interested in a job that would require him to defer to someone such as Dale Tallon, whose credentials are clearly inferior. Bowman wouldn't have taken a position with the Blackhawks if Rocky Wirtz didn't give him carte blanche with respect to team decisions. And I say that with full appreciation of Scotty's desire to be near his son, Blackhawks asst. GM, Stan Bowman, who was diagnosed with Hodgkin's lymphoma last year.
One of the first things Bowman did was hire Joel Quenneville as a scout back in September. Joel Quenneville's teams have made the playoffs 10 out of 11 seasons. With a resume like that, Quenneville is not going to spend his time in freezing cold ice rinks in places like Thunder Bay, Ontario watching 16 year-olds play hockey. Savard must have known this. Quenneville was hired as a head-coach-in-waiting.
Admittedly, the timing is a bit curious. It seems that if the change was inevitable, the team would be better served by making it as soon as possible. The only explanation I can find is that management recognized that Savard is extremely popular with the fans and that if it fired him without a reason, fans would be turned off at a time when McDonough and his crack staff of marketers have been putting on a full-court press to hype the team. The Hawks' slow start provided the reason they needed and management jumped at the opportunity. I don't like to think that hockey decisions could be so significantly influenced by marketing considerations, but to ignore the reality that the game is a business would simply be naive.
This infrastructure was implicitly confirmed by a euphamism the team used in the media. Savard's firing was described as an "organizational decision" by Dale Tallon during a press conference. In fact, most of those I spoke to who saw the conference on tv characterized Dale Tallon's demeanor as "stressed out." This would seem appropriate, since it has been demonstrated for all to see that Tallon is, in the end, a mere puppet to Bowman, which arguably makes him expendable. However, I think that Bowman's vision is to steer the ship while Tallon does the paperwork. This management infrastructure is fairly unconventional, but the Red Wings have shown that it can bring success.