Professionalism

I often wonder how can anyone claim to be a professional? What does professionalism mean? I do believe it takes on different meanings in different contexts. For example, I often flip through textbooks to see the content when I come across mistakes I regard the publisher to be careless and non-professional. I am not quite sure how can a reputable English school call themselves professional when they use books with mistakes in them. What are they trying to teach children? Of course when you speak a second, third language you should just do your best to speak rather than concentrate on grammar and pronunciation but textbooks with errors? It does not make any sense. Does professionalism mean wearing a suit? If so then I see this as purely cosmetic. The guy who goes to work in a suit shows off his so-called “smart” appeal to his boss but underneath he is just another slacker at work, stealing time from work. On the other hand you have a guy who dresses clean but with no suit and works four times as hard as the slacker. Who does the boss complain about? I suppose they are just all obsessed with appearance.