Mining has to become unprofitable for big business so they can die off and let mining return to the users.
This is a nice and utopic view, but I think that this is not possible with current terms (algo not changing).
Let's say that the businesses shut down and the home miner will continue mining (for fun, for believing in Bitcoin etc.)
What stops one of the big miners in, let's say, 3 months after shutdown to fire up all the miners and do a 51% attack?
Even thinking on that is scary. It would be the end of bitcoin reign, really.
If all the miners will be "home miners", the someone with a few ASICs can turn on and profit.
Then another guy with a few ASICs left on dust will see that the hashrate increased and that there's a chance to profit, and turn his rig on. And another guy, and another guy, and there goes on.
No network will die, no utopic "everyone mining" will be true(not everyone want a computer destroyed trying to get
BTC), things will only need another "balance". Also remember that most miners sell their coins to pay their rigs, so less coins means less miners selling amount that leads to a small rise in the price.
