One problem with having only a few producers is monopolies and cartels. What if they decide collectively to block transactions from certain services they deem to be competition? If a few entities cover 90% of block generation and you issue a transaction from a service they don't like, it could take a couple hours to get first confirmation. Or they could start screwing with the protocol, or any number of other devious things.
I agree with all of the above.
3 to 5 companies doing 90% of the mining will cause death to btc for the above reasons.
BTC is a money substitute for investors. Once a few companies do all the mining they control all the new transactions.
How would you want to hold 100,000 coins and not be able to move them because BITFURY held up the block they are in.
If we get to:
KNC
BITFURY
SP-TECH
AVALON
BITMAINTECH
ASICMINER
all self miners and the rest of the world shut out the system dies.
SP-Tech does have the idea for 5 or 6 people to share a few dozen 16kwatt units in low power areas.
At least it is something. I would want a piece of it maybe.
Killing off the home miner is a moron move. Making the home miner have heater/bitcoin device is viable. All across the world people use this item.