It’s great as long as it’s not used for theft. There seems to be a number of people on FR who talk about stealing stuff from property owners or public lands.
It’s also a hobby for people with strong ethics. Treasure hunting can make some people do crazy, illegal and dangerous stuff, but it’s definitely a hobby for adventurers, history buffs and people that like to get outdoors. A detectorist can find treasure that they can keep and sell, but when laws are broken, such as they have in Europe regarding cultural relics, the finder is probably tempted to skirt those laws and try to collect cash if the government doesn’t provide cash incentives to turn in such items to their country’s cultural ministry. I understand that the United Kingdom has what seems to be pretty fair laws around this and will pay cash for items deemed cultural relics. Just recently there was a rare Roman coin found that was deemed a legal find and the owner sold it at. Private sale for over 500,000 British pounds. The people that are going out to protected cultural sites in clear criminal attempts at stealing hidden treasures are not the people we want to associate with.