I think this is true inside a company, but it is another example of how weird our hiring techniques are. Writing plays basically no part in the hiring process. So for those engineers who have progressed by sharpening that skill, it is jarring to find that the barrier to their next job takes absolutely no account of it. You can spend years impacting or entirely setting the technical direction of a project or entire company through your writing (and verbal communication as well), and then find that all you're asked during your interview for your next job is to solve some made up problem using code on a whiteboard. It's bizarre.