I suggest you read Hayek's Road to Serfdom.
Totalitarianism under the urge to follow a "strong" leader by steering the sheeps against a "common enemy" is not giving choice to the market.
Having the requirement in place that 75% of the miners have to agree with this change first is in fact giving the choice to the market, considering that the miners would most likely not implement such a change without the economic majority also being on board as well. Hayek also defined totalitarianism as the desire to organise the whole of society and attain a definite social goal, this is also certainly not the case with XT.