Surewhynotlem is right...buuuut. Shorting is very much like betting, in that the more people who bet the same way, the worse those odds get; like how a bookmaker does things to balance cash in vs cash out.

The bookie reduces exposure by changing payout odds as betting increases on one side, so you win less and less as more people buy in on a specific bet over time.

In this case, the fees, which are the price of "buying" the short bet go up and up as more people get in line to short. That means the short has to go very far very fast to make up the initial share cost plus fees.

TLDR, you could short the stock, but so many people already have, the fees are starting to become prohibitive unless you have a large bankroll for investing.