Original
Short sellers cannot change the long-term value of a stock merely by making an outrageous bid. Besides, why would they want to? If a stock is "worth" $10, wouldn't a short seller be better off selling for the highest price possible, rather than say $8, just to depress the price momentarily. The market price would pretty quickly come back to fair value. It may be possible to manipulate markets in the short term, but not for long. I don't even think central banks can do that...and their pockets are a lot deeper than the short sellers you are concerned about. I think CB's lose money most times they try. Of course, this doesn't stop them from trying!
Real estate is a bad analogy, because it is not fungible in the way stocks are. There is only one of every house.
Maybe you're upset when short sellers are willing to sell at prices lower than you? But long holders can do that too. I don't like it any more than you when my stocks go the wrong way. But, hey, that's the market. And when it happens, the market is always right and I'm always wrong.
