Quote from 123Magic:
More or less. This isn't rocket science.
To use the university analogy again, some of the most prestigious ones have great scholars who teach courses and they may or not may be good teachers (which is subjective anyway), but at the end of the day, the student is ultimately responsible for getting the most out of the course. If the student fails the course, is it the professors fault when others in the same course received an A?
You can take horse to water, but you can't make him drink. More so with trading which dives into the emotions and psyche of the trader.
First off, size does make a difference, being a successful 5 lot trader does not imply you can trade 50 lots successfully, it's not just about risk and account size, there are psychological issues to deal with. There are also market factors, not all markets will allow one to trade 50 lots easily.
Second, just because one is a good trader does not in any way mean they can be a good teacher, coach, or mentor. What makes a good trader, the personality traits, often conflict with those traits that make one a good teacher.
Good traders tend to be slightly introverted, above average intelligence, and very competitive, we want things now, and don't have patience for BS, stupid questions, tiresome debate.
Teaching requires one to be patient, understanding, and more extroverted.
Through out history, the best coaches have always been good players, if not great players, prior to becoming a coach. If you are not a good trader, you have no business trying to teach and coach others!
If you are a new trader, looking to learn the ropes, keep that in mind.