I think the healthiest way to react to that sort of bluntness is to respond in kind. "I understand this isn't my decision to make. I just want to be abundantly

I think the healthiest way to react to that sort of bluntness is to respond in kind. "I understand this isn't my decision to make. I just want to be abundantly clear that I think it's the wrong judgment call, and here's why. I think it would be valuable, not only to solve the problem itself, but also to improve our working relationship if you show more value in my perspective in the future. I'm not interested in winning or losing. I am here to work with you." At the end of the day, one of you is wrong. If that can't be communicated well, then you deserve a better workplace.