A lot of noobs have "Get rich quick" mentality, they don't really believe in Bitcoin as a movement for freedom, so when we enter a bearish market, they start considering the possibility that Bitcoin was a bubble, a fad, a ponzi scheme, which makes them reach conclusion that they have to sell to get at least a portion of their money back. It's really dumb because even if you are into Bitcoin only to make money, you should analyze its long-term perspectives and its technology instead of thinking about from purely speculative side.
It's not just noobs that are spreading FUD about bitcoin. A lot of the fear and doubt is coming from rich manipulators and wall street guys that are looking to enter in cheap so they are doing everything in their power to crash prices. I think these people even have paid trolls to convince people online to panic sell and that bitcoin is dead.