Consensus? What does that mean? Hashpower? Non-mining nodes? Wallets? Percentage of BTC in existence (hodlers)? What arbitrary number would you like, if 75% is too low?
That means everyone. Miners, services, users, etc. You can't do this quickly and you can't do this with 75%. Essentially in order for a hard fork to be an upgrade the threshold has to be so high that the old chain has no chance of living else you're splitting the network in two. I'd say 95% being a minimum. Also, anyone arguing that a single entity could prevent the hard fork because of the threshold, the same can be said with 75% with just a small group being against it.
Your attack on Peter_R notwithstanding, I don't believe the absence
of a blocksize limit is necessarily a fatal flaw. You don't have proof that it is,
and to believe you know with certainty it is, is surely closed-minded.
It is either fatal or damaging. There's nothing positive about it. There's not a baseless attack on Peter R (Another nice example: subchains were gmaxwell's idea IIRC; guess who wrote a paper on them). His paper is based on assumptions and premises that aren't true in the real world. He definitely stood out at the first conference because he's a very 'atypical' "geek".
You're an advocate of decentralization right? Then EVEN IF there is an absence
of a fee market, there will be plenty of decentralized mining and security,
perhaps with a next generation Pow such as described here:
Yes. Two things though:
1. I'm not touching that forum.
2. We might take things way too far from this thread.