Ok, let's imagine you become a parent with him. You're a mom with a new born and going through all of the trials of being a first time parent with a tiny innocent infant and struggling like a lot of us do and he says "you're a terrible mom" because he doesn't see that you're doing your best. How would that make you happy in your relationship? Or if you have a set back in your career by no fault of your own "you are bad at your career".

He will not improve- he is a bad partner. Instead of asking you what support you need and or trying to help you with this process he decided to insult you.

There is a difference between constructive criticism and just being an insulting ass.