Of course, the attack you are talking about is not something that should be completely rejected, but I personally think that the people you are talking about do not have the courage or too much motivation to do it. Such an attack is a double-edged sword, because if they fail, what would it mean that ETH?
Yeah, that
is hard to guess at, I must admit. Maybe people are thinking too much about crypto as
one thing, and are not thinking much about the competition between the different blockchains.
But I can't help but feel like that could quickly change, especially if the Ethereum community starts being just a little bit vocal about this potential security flaw in PoW, as well as focusing on the narrative of being more friendly to the environment (and more cost-effective for the investors/users who have to ultimately pay the electricity bill).
As an anecdote, when I have talked about working on an attack vector to friends and family, merely the mention of the fact that it could save an electricity consumption the size of Finland's or Belgium's, or whatever it is exactly, immediately makes them quite excited and positively interested in it. Obviously there's a bias here to take into account, but nonetheless I can't help but feel that a large part of the public would be quite positive towards a change from PoW to PoS, and quite frankly perhaps even enough to be in support of Ethereum making a power move on Bitcoin in order to force such a change.
And as the original inventors of the 'Goldfinger attack' (Kroll et al.) argues (referencing an earlier paper by Becker et al.), maybe there's even a chance, however slim, that the public could go as far as help
funding the attack. Again, it might be a slim chance, but this is just to illustrate the point.
I'll say it again, I think you overestimate their power and motive - do you think the devs headed by Vitalik would agree with their attack on BTC? It is true that over the years BTC has gained a bad name due to some mainstream media reporting poorly on some things such as ransomware or the possible financing of terrorism with BTC, but it is never the tool's fault but the people who use it inappropriately.
But then again, since only a fraction of the stakeholders need to take part in funding the attack (and can do so anonymously), a majority of the Ethereum community could still be seen as innocent after the attack, even if the attack turns out to be disliked by the public.
No one would be innocent because you can't escape the fact that it was done by people involved with ETH - the very fact that these people (regardless of who they are) have such malicious intentions would throw a big stain on the whole project.
I honestly think you might be right about the fact that if we asked the devs and/or stakeholders right at this moment if they would be supportive of such an attack, their first answer would probably be no.
But on the other hand, I think that with the potential growth of their assets of around 100% or more looming on the horizon, that mentality is bound to slowly change over time, at least for a good portion of the stakeholders.
And because even the
talk alone about this security flaw could already start making slightly more investors choose Ethereum over Bitcoin than before, which would already make the preexisting stakeholders' assets grow in that case, I think they are
bound to start being more and more vocal about it at some point.
With so much money on the line, this contention will most likely reach the public sooner or later. And if the a big enough part of the public turns out to be in favor of a change to PoS, even perhaps by forcing Bitcoin's hands, then the Ethereum stakeholders (and devs for that matter, not that they are really required to take part) would have their green light to go ahead.