Ironically, the worst offenders are often the most "technical" people. It's like the old "comments bad, code should be self-documenting" BS. No, code is written for people, and software is written for people. Technology will always eventually bump up against its social and human context.
To be effective, you need to be skilled at both the code AND the written word, because these are all vehicles which are ultimately used to communicate with other human beings. Just like it's a myth that you can get into software in order to avoid dealing with those pesky human beings. Truly effective people understand their weak points and work on them; they don't pick a job that they think will enable them to run away from them and avoid them.
To be effective, you need to be skilled at both the code AND the written word, because these are all vehicles which are ultimately used to communicate with other human beings. Just like it's a myth that you can get into software in order to avoid dealing with those pesky human beings. Truly effective people understand their weak points and work on them; they don't pick a job that they think will enable them to run away from them and avoid them.