There is no problem. It's just highly unrealistic that such people can be found. And if they cant be found the end result is quite clear. Hashrate will drop to

There is no problem. It's just highly unrealistic that such people can be found. And if they cant be found the end result is quite clear. Hashrate will drop to the point where attacks are possible and will occur. Or more likely non-profitable miners will do the final double spend scam before turning their hardware off. Or they go bankrupt and someone buys the hardware cheap to do the double spend after the difficultly adjusted. Either way BTC can not become the ham radio niche thing. Its endless growth or fatal failure.