That's to be expected, isn't it?
Bitcoin priced dropped so much compared to late year. Customers who has bitcoin are likely to have purchased them at a much higher rate than the market price. They will be at a loss spending their bitcoin. It is "cheaper" for them to pay by credit card. Merchants who accept bitcoin can only expect bitcoin transactions to pick up after we see a surge in price.
I'd only be willing to reward companies that take bitcoin as a payment option if they offer appropriate discounts to make it worth my while. If they aren't willing to help incentivize more people to want to pay with bitcoin by offering these discounts then they deserve their fiat or less business in my mind.
I could comfortably say that they prefer fiat over bitcoin. Accepting bitcoin is a PR gimmick for them.