These users who spreads fud always receive some attention and when they get noticed they'll continue posting. They want everyone to suffer bring their hopes down and feel bad about their investment. Others want you to stay away from Bitcoin and invest on different things like silver or altcoins. I sometimes think they're getting paid by a whale or the government.
Nah, I doubt whales or the govt are involved in the FUD campaign we see in this forum whenever there's a big drop, they have enough power to actually spread FUD on a major scale by using sites like cnbc, cnn, or bloomberg 
and it's not like FUD threads in this forum are going to have a major impact on the market so why would they even bother to come here? People just generally blame anything they don't agree with as FUD without regard to the merit of the argument or not. Of all the things that get labeled as "FUD" by the hivemind on these boards, maybe 5% of it is. The other 95% is just rejection and mental shut down by people who don't want anything to interrupt the get rich quick and lambo dreams people buy into when they buy Bitcoin. Ultimately, people fail to recognize that at these price levels, the easy money is long gone and nobody is going to become a Bitcoin millionaire from this point on just by buying and holding Bitcoin, at least not without significant risk that doesn't justify the risk:reward profile. But if you try to tell them that, it's FUD of course!