Profitable home mining may become a myth, but home mining won't die. If it did, Bitcoin would slowly die, since the real believers of Bitcoin are the home miners and hobbyists, students and researchers. These are the people that actually give Bitcoin value.

The farms in China and the investors behind them know very little about the bitcoin ecosystem by comparison, and they do things and act in a manner that is actually harmful to the future of bitcoin (decentralisation, SPV mining, mining empty blocks, pump and dump, monopoly of control of hardware, and harm to the environment, money laundering, ponzi schemes, and mining with customer pre-orders). They are very much in it for the short term, trying to milk as much money as possible from it so that they can divest into other technology areas once they have killed the bitcoin cow.

Home miners were mining before Bitcoin had any real value, and they will still be mining at crazy difficulty without any hope of profit provided the network is healthy. Home miners stopping in droves would be a very VERY bad sign, since it would mean that the people who understand the technology the most and are the most die hard supporters of Satoshi's vision, have lost faith in the network. That would be far far worse IMO than any crazy high difficulty level or electricity cost.