Precious metals are popular vehicles for tax evasion, sanctions evasion, terrorist financing, and money laundering. Relative to how useful they are for such activities, it's an industry with very loose if any regulations and oversight.
It's an industry that's about to start facing a lot more regulatory intensity.
As for why this man lost his bank accounts, only the bank knows. Usually when banks close business accounts for customers that have been around for a while, it's almost always due to the account being inactive or seeing very little use (doesn't seem the case here) or because the bank has changed their risk appetite/focus markets.︀ The bank may have decided that compared to the size of business (i.e. how much︁ money the bank made) it was no longer worth the risk. Or maybe the bank︂ is closing all similar business accounts and shifting towards more profitable businesses.
Another less likely︃ possibility is that the off-boarding was triggered on reputational grounds. You see that sometimes with︄ politically motivated businesses and organizations, which may lose their bank accounts if a media controversy︅ arises. I'm not sure what that would be in this man's case, though. Maybe some︆ controversial coinage with historical, political, or religious connotations that somehow became known to the bank.︇
More likely, it's just a change in risk appetite with the bank.
Or he has︈ massive, unpaid debts or something obvious like that.
