The more or less accepted consensus that MS-Word should be chosen as standard was in effect in some areas of documentation. This is not true anymore for customer documentation.
MS-Word is clearly both a good and a bad choice, depending on the point of view: not any single documentation tool or platform simply cannot fulfill all the documentation requirements of a SW product. For example, customer documents require high typesetting quality, not strictly needed by technical documents, customers require hard copies, easy to access and to annotate, designers don't and prefer fast on-line access to the information, etc.
In short, customer documentation platforms should be different from internal documentation.
During many years, SW product lines have been misleading themselves by considering the need of a single documentation style. The reality is different, and therefore, we should implement internal documentation differently than we treat external documentation.