How does people find out his apprentices are free labour? Even if that is the case, what's the problem with it?
There are many professions in which the apprentices learn by doing a supposed paid job. I highly doubt every single bespoke suits are only touched by the master coatmakers/trouser-makers. Ask some of those Japanese shoemaker apprentice and see what they say.
Do people still don't understand the beauty of corporeal personality in the 20th century?