I think there's probably a perception issue at play too. Buying a pirate decoder card from a shady dealer is 'obviously' wrong, while using a subscription that

I think there's probably a perception issue at play too. Buying a pirate decoder card from a shady dealer is 'obviously' wrong, while using a subscription that you've already paid for in a different location is a different matter. I could see pub landlords being more comfortable doing the latter than the former. I don't know what the current state of the art for pirate decoders is, but if it still depends on extracting a keystream from a legitimate decoder in real time and sending it to the pirate receivers, limiting the number of legitimate receivers of the business channel to would also help cut down on piracy of the business channels by reducing the possible sources of key material. The high cost of a subscription and limiting subscribers to pub businesses only also reduces the number of potential key sources.