If you think of rigorous code reviews as brutal, you're seeing it the wrong way. Reviews are about the code, not the people that write it, and the process of reviewing means teaming up to make sure it will be the best it can be.
If its really sloppy, bend your boss' ear and see if they agree. If so, develop a plan of action with your boss to get things up to standard for everyone.
If it's sloppy and terrible and no one wants to change, find a new job.