Given the cost, you can't mine empty blocks for long even though the blockchain can support empty blocks and will support the longest chain
That type of attack you describe would be prohibitive in terms of cost
I understood that empty blocks do not cost more to mine than normal blocks, and pay the 25 BTC reward just like them. Isn't this true? (Transaction fees are still negligible -- less than 20 BTC/day, compared to 3600 BTC/day for rewards.)
According to the script I described, the cartel does not need to increase its hashing power during the transition, and does not
lose the block rewards, whether it succeeds or fails in the attempt.
[jamming of the main chain] doesn't invalidate past transactions or future ones or constitute a change to the protocol supported by the p2p nodes. Transactions resume after the attack.
Users who do not upgrade will have their bitcoins blocked for as long as the cartel wants to. Meanwhile, users who upgrade early will not even notice the transition, and those who upgrade after the deadline will immediately recover access to their coins.
if successful it would render Bitcoin useless
Why? Objectively, it would be as if Satoshi himself had written "2018" instead of "2016" in the reward halving schedule.
Do you mean that it would show that the protocol is not resistant to change, as many believe? But, unless there is a flaw that I still can't see, the plan
could succeed. So bitcoin is
already useless?
given the cost to participate un-cooperatively, any actor would stand to gain more by cooperating.
Exactly.