Somewhere in the troll's post, is part of the answer on WHY anyone who can afford a 51% attack will never dare actually do it.
A potential attacker would need to act economically irrationally to successfully launch a 51% attack, when only looking at the attack in terms of bitcoin.
This means that bitcoin, or crypto in general would need to be an immediate threat to whoever is launching the attack. I don't see bitcoin being this much of a threat to any entity with the resources to pull off a 51% attack.
That "economically irrational attacker" would be wasting resources. The network is made of people, capable of coming to consensus if there was a direct threat.
What the troll said was that the miners could collude. But would they? They would be opening a strong debate for a POW change.
The mining operation would lose money, however a potential attacker would not be trying to be making money via mining,
but rather would be trying to profit by harming bitcoin, or maybe would be trying to avoid losses by harming bitcoin.
A potential attacker would be one with a lot of resources, and a lot to lose if bitcoin were to succeed. A potential attacker could either buy up mining equipment, or if it was a government entity, could seize miners physically located within the country.
OK. But first explain how a bad actor could off-set the potential wasted resources from a 51% attack, and would that it be better to profit through honest mining.