The Red Sox took their best baseball trade chip and traded it for suboptimal return strictly to save their owner some money. That warrants criticism on its own, and when it is a high revenue team that can afford to make baseball moves for baseball reasons, it really smells. It is possible to both be okay with how ownership has spent in the past while criticizing the decisions now. There have been very few moves Henry has made in his tenure which have been bad faith - this is one.
Second, even IF we accept the sympathetic framing ... that the Red Sox have actual affordability problems and payroll needed to be reduced for reasons, this was a problem apparent entering the 2019 season and yet management proceeded making multiple dicey spending choices which boxed them in here to feeling like they had to trade their best player without harming the Dodgers internal prospect rankings.