The quality of a team is the quality of the communication. If the architecture and design isn't well communicated, you get people going off in the wrong direction, or polluting a clean design. Also, people are most attached to their code based on their time investment. If you trash someone's code/changes, you trash their time, which could have been more efficiently decided with a conversation ahead of time. If you find yourself surprised by design changes, find design flaws in a code review, or have different definitions of "improvement", the communication in your company may be lacking.