Why do these big Bullion retailers except bitcoin for payment for gold?

A year ago i bought 5 oz of gold with Bitcoin. I was lucky i got into Bitcoin around 4500 and sold all of it on the way down at 16500... With that said I've been wondering ALOT lately why these big bullion retailers are excepting bitcoin for gold???The ones who are in charge of the fiat system are not dumb and are many steps ahead,Prepared for the dollar to collapse. We do know that they want to go to a cashless society.Possibly Crypto currency is the future? Which is why i continue to wonder why these retailers are willing to part ways with gold for Bitcoin.Do they continue to hold BTC or do they sell it off? I am hoping someone here has some info or any ideas.Thanks.