I actually think the frustration is justified in this instance. This isn’t like Napster, where you kind of knew it was illegal all along…or even worse like running cable from your neighbor’s house or tapping into your neighbor’s Wi-Fi. They literally promoted sharing your password and then flipped.
This is more akin to having kids eat free, and the restaurant has always welcomed you with open arms, and then one week you show up and they not only don’t apologize when they share the new policy, but they rub your nose in it by telling you the restaurant is only for people who pay for everyone.
I’d find a new spot, but I’d be pretty mad in the moment that handled it the way they did.