This advice on clothing is an extension of their brand building strategy.
As I see it, the doctrine of blood avoidance (nowadays anyway), calling the buildings kingdom halls, describing themselves as "worshippers of Jehovah" instead of christian, is all part of a brand building concept, whether they realize it or not.
JW's MUST stand out, especially in the convention cities. The cynical part of me says that they GB wants the entire community, including the convenience store owners, restaurant owners, etc, to see JW's by their badges and geek clothing and NOTICE them. Notice them as well dressed, affluent (hey, they will spend money in MY place of business.)
Face it, this is just a business stragegy. Like quick build crews in New Orleans, quick build halls where they are not needed, as in my town, like not having food any longer (to avoid paying sales tax and cloud their tax exempt status), like not "charging" for literature any longer (same tax exempt status), like dumping bethelites and saying that they are needed in the congregations.
They are a vicious corporation hiding as a religion.
When you have a brand name and image to protect, you will tell the franchisees to tow the line, or else.
