Some people may need a mentor because they can't grasp the theoretical lessons online well enough. What they need is an interactive teacher, mentor who also functions as an instant corrector. Getting a mentor usually shortens class time.
Life is about believe and determination. If someone is patient and reading to understand about trading, he will sooner or later know what that are necessary to be known in trading. Like I said, the most important thing in trading is the strategies used, like not risking the amount of money that you can not afford to lose to trade, not using leverage, overcoming emotion, having a trading budget and do not go beyond it, averaging and some others.
But he has preferred to go for a mentor which I do not also think that it is bad.