I also think if the effect on liquidity won't be dire, making the 30 day cover rule much longer would be better.
We all need to come up with a new, better idea for how to ensure that shorts cannot short eternally to 0 and never cover, because the 30 day rule isnt working well and is hurting people.
But we cannot simply remove the rule and replace it with nothing.
Of course, if all the market making bugs were fixed it might not be a big issue anymore, so perhaps that is the solution.
We need to look at how supply is introduced on centralized exchanges. Supply is introduced on centralized exchanges when users deposit coins and supply is reduced on centralized exchanges when users withdraw coins. When supply is introduced, an IOU token is issued to the user for trading and the exchange becomes custodian of the actual asset. If coins are not deposited, then order books are thin - just take a look at some of the order books for some of the lesser alts on centralized exchanges. In some cases, such as the gold and silver ETFs, shares are created when the exchange purchases the underlying asset for the user.
Supply is introduced in bitshares when units are shorted into existence. If a user wants to deposit bitcoin, they will be buying BitBTC from an existing seller or short seller. Supply is reduced when existing shorts cover. Forced covering forces a reduction in supply. Would a centralized exchange have forced withdrawal? Futures contracts, for example, have expiration dates (mainly to generate fees) but expiration may not work well with units that are intended to also act as currency.
Users won't eternally short to 0, especially with the price feed. In fact the opposite is occurring right now. Look at the btc, gold, and silver markets. There is very little on the ask side. I, for one, have refrained from shorting because of the 30 day rule and I have been prevented from buying assets because of a thin ask book. It's like a double-edged sword. I think we should at least scale back this requirement to maybe 90 days, then 180 days, ect and see how that goes... and maybe eliminate the rule entirely eventually. I know the rule was meant to increase liquidity but it didn't work. Mores users will be required to increase liquidity and we may attract more users by removing the forced covering rule.