Individual investors typically do not short stocks. Especially a hard to get stock like TSLA where the cost is 20-50%/year! Besides a significant margin account, need a relationship with an institutional broker that will search for shares to borrow, and they do not do it for a few shares. What individual investors typically do is buy put options.
I suspect it is mostly paid shills like interns, or folks hired indirectly that post persistent negative stories, persistently. I imagine it is a way to make money from home. The bad part is that they have betting against Helicopter Ben lately. Shorts used to be smart... but seems they all piled on the same stocks like SCTY, TSLA, SODA, etc. Tesla still has a relatively hi short interest at 17% of the float.
i promise you they dont. the only ones on message boards are brainwashed longs and option players. But the boad does have a purpose. Most of these people always wrong. So I use it to take a stock's temperature. Doing the opposite will make you rich.