my fav bit.
Bitcoin will have a hard-fork, eventually, I think. When bitcoin has a HF, there will be 2 chains after the fork and there will be 2 coins. It is almost guaranteed that some people will refuse the new chain and will remain on the old chain. There are enough people with significant amounts of bitcoin who will never agree to a fork and can afford to keep mining the old chain. Ethereum demonstrated this issue very well. In bitcoin it will be much bigger, because the old bitcoin may be worth as much as all of ethereum (1 billion USD). It will not undermine bitcoins value very much, but it will cause some chaos with users, wallets and exchanges. This is why a HF needs to be very carefully planned and executed with plenty of advance notice. We also need to learn from Ethereum and consider adding some anti-replay defenses to help users maintain separation of the two chains in their wallets.
I think hes right eventually we will HF but hes exaggerating the possibility of a chain split as a result IMO. if Core is supporting 2MB hardfork when the time comes ( in like 2years? ), i dont see a chain split as a possibility. I guess maybe there could be some die hard group that rejects the fork with <1% hashrate...but its not like the HF is proposing to alter the immutable blockchain, or something equally ridiculous. I disagree with the idea of adding some anti-replay defenses, the other chain should be viewed as INVALID, and there's no use catering to an invalid chain...
A 5%-hash chain of BTC will be producing blocks at something like ...200 minutes. And with difficulty adjustment in 10 months (which will not fix the issue) it'll be DOA.
It would require proof-of-work change and diff starting from a lower point. So then you have 3 coins and the one is unusable.