Coaches get fired midseason sometimes and it's not always about bloodlust. First, it takes away the speculation about the future. Second, it gives someone else a chance to close out as the interim, maybe show some good things. Third, it lets us start the transition early. The players, fans, and everyone will know change is coming. They'll be fighting to shape the new era in their last two games instead of under the illusion that anything they can do will save their current coach. This doesn't need to be a wound that opens up when the decision comes down at the end of November.
I'm as high on Riley as anybody. If for some reason they're still entertaining keeping him, I'd be happy to support Riley next year, and crazy/optimistic enough to think it'll be a lot better. But right now, we're just dragging this out, and it's agonizing.