Right or wrong is acutally relative. From your point of view or from technical point of view, it may be right. However you may not be able to see the whole picture at your position, but your manager does.
I also have a lot of this kind of experience. My team members also argue with me of my decision. Sometimes I can't explain to them because of some political reasons, sometimes because I have my pressure from my boss, sometimes because I have some other considerations that I don't want or I can't explain to them. I also say "Just do it".
Easy.Spin is absolutely right. The only thing we can do is to improve ourselves and it will only benefit ourselves sooner or later.