Well, that's the problem, isn't it? At the outset, not only is it hard to tell whether an apprentice will stay once trained, but also whether they'll be any goo

Well, that's the problem, isn't it? At the outset, not only is it hard to tell whether an apprentice will stay once trained, but also whether they'll be any good at what they're being trained to do. It's doubly risky, which explains a lot of the reluctance to take on apprentices.