The stable coins I'm guessing you are referring to (e.g. USDC and USDT) require you to trust their issuers.

We're designing one that requires less trust. Is this the only way to do that? No, we could have chosen other mechanisms. But this was the easiest tweak I could see to the existing code to stabilize the peg for HBD without requiring some external entity to promise to back it dollar-for-dollar.