Indeed they are pretty much the opposite of something that is going to be successfully shut down or even regulated by the government any time in the foreseeable future. If anything that is a lot more like the pot grows mentioned in the OP, which to me seems like close to a best case for decentralized PoW mining. (I'm not sure whether that is better or worse than end users just running a mining client like Bittorrent, but it seems close.)