As I pointed out, the Kings were only 4-8-1 at the time. I don't understand how anyone could feel that the season was lost at that point, much less the person who was so confident in the team that his only Summer move was adding a 35 year old. GMs just don't bring in coaches to tank, especially not in early November. Respectfully, I think that that's a fan fantasy, much like the notion that teams or individual players tank. Can you imagine if it got out that a GM knowingly picked a coach to fail? He'd lose the respect of the hockey community, and I think that that's something that Blake, especially, cares about.
I believe that the simple reason that Blake hired a bad coach is that those are the only kind without a job on November 4th. The pickings were very slim. Desjardins likely would not have been Blake's first, second or third choice for the job, ordinarily, and I think that that's why he was given only the "interim" title. I'm criticizing Blake for many of his decisions, but at least he had the good sense to not commit himself to Desjardins, so that he could (if Willie didn't work out) conduct a proper search at the end of the season, when the available candidates are much better.
One more point that I'll throw in is that you don't sell low on a player like Pearson, and especially in exchange for a UFA to be, if you've lost hope for the season. You do that only when you're desperate to shake things up. It, otherwise, would've been much smarter to see if he would've rebounded and neted a higher return at the deadline or even just see if he has a better season next year. As far as I'm concerned, selling low on Pearson strongly suggests that Blake was still trying to salvage the season at that point (and, for the record, that trade occurred 10 days after the coaching change).