I think you’re misunderstanding the user of the term “public” here. A mall is a public space in the sense that people can go, but it’s not a picnic space in the sense that it’s not operated by the government, it’s a private space. I’m using the term public space in the governmental sense, not in the publically accessible sense.

Also, talking about Europe as a whole is wrong since different countries can still have different rules on the subject.