To be honest, you really can't separate the doctrine out when you are talking JW. Everything they do is based on doctrine.
Everything accomplished in the organisation is supposed to be done for the glory of Jehovah.There is a huge emphasis on their doctrine that "the world is passing away," and that one must always be on guard not to get caught up in "worldly things" (ie anything that doesn't advance the preaching work).Groupthink is the accepted mode-not individuality. Gifts indicate individuality and a direct link with the creator (which the WTS vocally denies with thier "faithful slave as mediator" doctrine). Independent thinking and doing is counterproductive to a groupthink society, so anyone who exhibits these characteristics are disuaded from continuing to do so. Usually, they are "counseled" that to use gifts for anything except field service will cause one to be "puffed up with pride," and glorifies the created rather than the creator. In actuality, the risk is that having and using individual gifts exposes one to OTHER MODES OF THINKING than the JW mode of unquestionably obeying the "faithful and discreet slave"/ governing body.
When a person first gets involved with the JWs, there isn't such an emphasis on avoiding use of gifts for other endeavors. It's usually just hinted at (lest the potential convert be scared away), and the person is constantly directed to think how they can use that gift to serve Jehovah. But, if the gift isn't useful in promoting the conversion of new members, there comes a time when the person is encouraged to put use of that gift away "until the New System." Anyone who refuses to do so is then leaned on harder, and basically labeled unspiritual, selfish, or worse, "worldly" if they continue using their gift.
JWs are taught to live for advancing the "only true religion" (ie making new converts). ANYTHING that conflicts with those aims is considered satanic.ANYTHING that even has the potential to have a person question the authority of the governing body/FDS is satanic. ANYTHING that involves time away from constant indoctrination at meetings and studying the JW books is considered satanic.
Edited to add: They may not directly say this, but if you read enough of the personal experiences and other articles in the Watchtower and Awake magazines, and attend enough meetings, assemblies, and conventions, you get the underlying message.
And some of the more zealous JWs do come right out and say it.
