It is theoretically possible to have 100% legitimate retail sells show up as 100% shorts in the daily finra numbers...
Consider someone selling shares through their broker. There are two legs to the transaction, the MM selling the shares into the market and the MM taking ownership of the shares from the seller’s broker. There is also a possible third case in which the MM just buys the shares from the broker to complete the sale and holds them (as MM's can end up with both short or long positions in a stock in an effort to make a market). In this sell case, if the leg of the sell transaction from MM to the market is counted, the sell will (somewhat surprisingly) appear as a short in the numbers if the MM sells the shares to the market first before taking ownership of the shares from the broker (as the MM may sell short to the market first knowing that he’ll immediately get shares to cover from the seller’s broker). If the buy from the broker to MM leg (or the buy to “hold” by the MM) is counted, the sale will not appear as short. Only one leg of the transaction will appear in the daily numbers to not confuse the volume numbers.
Buy transactions are equally confusing as they also have two legs. The leg from the market to MM and the leg from MM to broker. If the leg from market to MM is counted, the buy not will show up as short (as the MM bought shares). If the leg from MM to broker is counted, it will show up as short (as the MM sold shares to the broker). There is also a third case in which the MM sells his own inventory to complete the buy (which will likely not show up as short) and a fourth case in which the MM sells shares it doesn't have (naked shorts) to complete the sale. This naked shorting is legally allowed so that the MM’s can make a market.
In general, the finra numbers are supposed to tally only the "consolidated tape" transactions, that is the transaction legs between the MM and the market (not the legs between MM and brokers--called media transactions). This has the effect of often having a large number of legit sells (possibly even all of them) show up as shorts in the counts.
If this was confusing, that’s the point. Exactly what a short in the daily count means depends on a variety of factors including exactly when and in what order a MM completes the two legs of a buy or sell transaction. High short numbers might very well indicate a high number of legitimate retail sales.
Again, not disrespect and I don't want to see anyone losing money, but shorts are not the problem here in my opinion.