This move isn't about this season. It's about the long term health of the ball club.
They're basically hitting the reset button after Dombrowski threw all of their money at the major league roster, while ignoring the farm system. You can only do that for so long before the bill comes due, the well is dry, and now you have a roster full of overpaid, underperforming vets, with no talent pipeline behind them, and you're screwed for a decade. That's the road they were headed down.
They gave Dombrowski too much leeway after winning the World Series, which was a mistake. But they're admitting that mistake. They've course corrected, sanity has taken hold, they've pulled the rug out, and now it's back to reality.
For the long term health of the Boston Red Sox, this is a good thing, not a bad thing.