Shorting can also help investors in the market at large if it helps bring down companies that are obvious scams. Some short seller reports have pretty famously destroyed companies that were up to no good, preventing further harm to future investors and boosting confidence in the valuations of the rest of the market. If there's no money in doing all of those short seller reports, then people won't do them, and the market will have less information available to it in total, and more frauds will continue to go under the radar.