Thats just my point. Those in the know ,know what they are getting, those who have just discovered e.g.clogging, Irish dancing, don't know the subtleties. At a festival you dont have time for deep research in the programme, it should be self explanitory. And by the time you've trudged across town and found out you've missed 2 other workshops you would have enjoyed.

Local usage is a bit different, it only confuses visitors, at a festival everyone is a visitor.