This does not really work in practice, it is only a theoretic argument because in shitcoins everything is extremely centralized around the original team that creating a viable opposition is not practical. We have seen many cases whether of chains or tokens where the founders did all kinds of things that are bad and many in the community disagree with it but ultimately they had to accept it, there were very few examples of opposition like ETC.
Imo it depends on the degree of centralization. Of course, on super-centralized coins (say something like Sui or XRP) any opposition would not have any effect.
Zcash had, in comparison with coins like Ethereum, a relatively small premine (the dev tax would make up 10% of the total supply). The Ethereum founders in contrast premined 50% of the supply of the first years, even if they sold a part in an ICO. So they had more threat potential to dump the ETC coins. In Zcash's case probably a strong community still could create pressure.
It's however a bit a point for your side that Zcash seems to have extended its dev tax, and they were able to do it without a major hard fork (see tromp's answer).
I have never lost any coins and neither did any people that I have known, so any extrapolation from big cases or known cases will be extremely suspicious and speculative with high inaccuracy.
I know people that have lost coins. It was only faucet rewards or small gifts at that time (pre-2015) but it would be worth at least some hundreds or even thousands of USD today.

This is one of those cases where we should be publicly admitting that there simply is no way to provide a good estimate for this instead of speculating and making things up as some of those examples did. Any metric that you use is not going to be true, like using number of days since coin has never moved or public admissions of lost keys.
I think if they really thought there would be at least a chance to get the order of magnitude.
For example, you could combine:
- a good poll on long term holders' behavior ("good" means: not a simple online poll, but at least an online panel)
- another good poll on lost Bitcoins
- the Bitcoins that are not moved since a year (5 years ago for example)
Most estimates are based only on one of these indicators, above all the "not moved Bitcoins". But that's too shallow. Ideally you do several polls over a timeframe of at least a year, and then contrast them with on-chain data.
I have found out that the Cane Island method is even worse: they derive their number from money that is "typically" lost in every economic system (e.g. lost banknotes and valuables, lost access to payment platforms or prepaid cards ...). But even then: Do you really lose 3-4% of your money per year? I've seen estimations of 1-2% but I think it's still a bit high.
Only if there is a proven issue that is happening and requires an emergency measure
Agreed. However it hasn't to be necessarily a 51% attack in progress. I think if Bitcoin had only a (raw, i.e. not marketcap-bound) attack cost of 2013/14 levels or earlier, then I would be worried and support such a measure.
Bitcoin would have been much better off with a tail emission. Not in terms of marketcap, which due to a reduction of FOMO and speculative use would have been much lower,
I disagree that it would be much lower. I think the missed FOMO and the FUD about the security budget (which is a type of FUD that even "could" have a litte truth in it) should be roughly equivalent. The whole "mining death spiral" theory would probably collapse too, because it heavily is derived from the argument that the security budget is "too low due to the halvings".
This even strengthens your point however

(Zcash messed with its policy when its developers reneged on the original 10% premine by continuing the 20% dextax beyond the first 4 years).
Thanks, I was just looking for the answer of that question to answer Dogedegen's post.