that's not necessarily true at all. some people are df'ed after they've been on a bad course, and that's what they need to get back on track. i've seen it happens. it's definitely not wrong to pray for them. i'm not making excuses for people, but sometimes people just mess up, or sometimes people are under so much pressure that they're not ready to handle it. DF'ing is a loving provision for them really.
yeah it' s Jehovah's last stitch effort to get them to come back to there senses.