if the posts are related to the things you are working on, then writing about them, during a break, it could help you not get distracted in case you did something else totally irrelevant.
It's still a bad idea to associate blog-writing skill with technical and even interpersonal skill. It's also a bad idea to make too many assumptions about the reason why someone might choose not to have a blog. A guy with a family might not want to risk getting the wrong sort of attention, for example.