But look at HBD in DHF as this.
Say a short seller want to do the same things as to LUNA and UST.
He will need to get a lot of HBD first, as they got 1B in UST.
All the HBD in the DHF is not for sale. A maximum of 1% can be sold daily if someone push the price of HBD up. Its impossible in a short period of time to get a lot of HBD. HIVE to HBD conversions will be needed and the HIVE price will most likely go up.
Next even if by some magical scenario someone gets a lot of HBD, when they start to short, HIVE price drops bellow debt limit, and HBD loses its value as well. Unlike the UST case where they try to maintain UST price, while LUNA was going down, giving the UST holders a lot of LUNA in the conversion process.