If a business providing free wifi that requires a password wants to make it easy for people to use its wifi and provide easy access to the password, obviously that is the choice of the business. Although I think most businesses ideally want to encourage interaction for a person to get the password (ideally, positive interaction with your well trained staff - in the real world of small business food & beverage operations, good luck with that) but I have seen some places where the password is posted for all physically present to see. Maybe there are lots of examples I have not seen or do not remember, but I do not recall any provider of free wifi that requires a password post the password online. I think that is what stands out as different in what the OP did. If a business wants to post its password online, I think that should be the decision of the business. I think it could be reasonable to find little difference in sharing knowledge of a password between friends sitting on a beach (just a hypothetical of course) and posting it online - but I think it clear that most find that it crosses a line.