I'm not sure why that bothers you. Saying its required keeps more people wearing them without the hassle of forcing people making minimum wage to be confrontational with customers. It's honestly the best way to slowly transition from wearing them. Not to mention it's the best way to not alienate customers. The sign is there for mask nazis, but it's not enforced for the "this is a free country" crowd.
So why use "required" as opposed to "encouraged"? I'd be 100% on board with a sign reading encouraged and think at this point in time it would be just as effective. As I said, I take issue with the word "required" because they're not requiring a damn thing. They're puffing out there chest using a word with a powerful meaning yet not doing a thing about it.
Like I said, I have absolutely no issue with a company encouraging masks or giving customers the choice. I do however take issue with anyone who puts a policy in place yet has absolutely no intention of enforcing it. What's the point of a policy that isn't enforced? If it's not enforced and there's no intent to inforce it, is it even a policy? Why even have a sign in the first place?