I read that article before. It is mistaken; users do not have voting power, because their only options are give in to the cartel or lose their coins. Note that any entity that can jam some process for a sufficient time can force the users of that process to accept anything that is not as bad as the jamming itself.
You need to read it again, until you understand it.
If a cartel of miners tried to block all transactions, there would be code for a hard fork within 3 hours making some trivial change to the PoW that rendered the current mining industry worthless and the hard fork itself would probably happen within a few days. And then life would continue on as usual, except that the next set of miners would know how suicidal such a move would be (and on a more contemplative schedule further changes would be made).