I suspect many of the ultra bear posters on here have heavily shorted and want to drive the price down so they can buy back really cheap bitcoins. If it's true they will probably start making ultra bull posts after the price starts to shoot up and they are forced to buy backin at a higher price.
Yes everyone posting has an agenda. Of course bitcoin holders are honest about it, unlike the bearish 'buy back lower, but really believe in bitcoin' crowd.