Your clients are not your bosses though, they are your clients. In your traditional office environment, for example, it would be unusual for the business's clients to require visibility of the business's computers.
No, but for example in my last office job the 3 company founders tended to be walking along the main hallway of the office a lot for various reasons, and my desk was behind a glass wall along that hallway, and in one gig i was in an open plan office where people were moving around me and everyone else all the time.
I'm from Germany too and as far as I can tell this isn't the truth for every company here. When I find clients/employers behave like that, I warn them and then I quit. This is what everyone should do. If you accept such horrendous conditions it's your fault people begin to think this is "normal".