I have a very good idea why that statement was made in the KM to begin with. Like most other statements, it was to COVER THEMSELVES LEGALLY.
Here's the situation: There are countries who do not recognize religious organizations who do NOT VOTE. THEREFORE... WITNESSES IN THOSE COUNTRIES ARE ACTUALLY ASKED (demanded?) TO VOTE. Please note!!! The unwritten "understanding" is that they vote for EVERY candidate in the running, thus cancelling out any valid "vote". BUT who would know the difference? There is no way the elders would know.
A friend of mine has family who are missionaries in such a country, and yes, they "vote" as Jehovah's Witnesses (Gileads, even!)
I am going to go looking for backup threads on this, if anyone finds them first, please let me know.