If he can use Bitcoin as an investment and have a main job, that is better because he can earn money for his daily needs. If he depends on Bitcoin and uses it to fill his daily needs, he needs to have many Bitcoins and sell enough amount for his daily needs. Maybe he has that many Bitcoins so that is okay for him. We can not blame him for doing that because he should have calculation or considered before doing that. You are not wrong in saying that because you know about the volatility of Bitcoin.
No matter how much he has, if he wants his bitcoin to keep growing he should just leave it alone and not keep getting from it. Without a source of income he will just keep getting money from the stash of his bitcoin until there is almost none.