> who took the view that all short positions were ursary
It's more than usury. There is usury involved because "lending" the stock is done with interest. However, the problems don't stop there.
Stock shorters, as you point out, actively bet against a company or industry or economic structure in general, it's their benefit to see a company collapse or not do well. This isn't how a stable society should be set up.
Furthermore, stock shorting exposes three parties to risk: the original owner, the shorter, and the new owner. There is risk being created in the market that does not justify the value that comes out of it. Let alone the fact that it's possible to short more than 100% of the total stocks, on what planet is this even acceptable? In a normal stock trade, risk is transferred from one party to another equally.
The conclusion is that shorting is a heavily immoral, predatory, and dangerous practice. It's quite ironic that when ** hits the fan, the government has to step in to limit certain trades or practices that we've known all along to be dangerous (e.g. they lower interest or ban shorting).