First past the post is dangerous

The danger of not having democracy is that the state (being unchecked) is able to expand indefinitely, which will lead to universal poverty. For the state not to be checked by democracy is very dangerous for the people because it will expand forever. Without a democratic check on democracy the state will consume everything which is why democracy is important.

When the first-past-the-post system is used this is partly democratic but not full democracy and once the centre-right party is no longer widely-supported it tends to a one-party state of the left. Historically, people have voted for the centre-right party in a two-party system because that party is more closely aligned with the church, but as this becomes less important for people, then fptp becomes like a one-party state. One-party totalitarianism is a threat to he survival of the people because when the state is unchecked it consumes everything and there is no material wealth. When the centre-right party is no longer widely supported fptp becomes more like a one-party totalitarian state which is dangerous.

Fptp favours the state because it favours the big two

The essential problem with the first-past-the-post system is that it tends to encourage a two-party system due to tactical voting. Voters know that only voting for parties which will do well is worthwhile and so they will not consider the minority parties and this feeds on itself to the point where there are very few parties remaining, usually two. So a multi-party system becomes a two-party system under first-past-the-post.

Defenders of this system (usually from one of the favoured parties) will claim that to favour bigger parties is not to favour the state and so fptp is not anti-voter it is merely pro the big two parties. It is generally assumed that laws should not be 'statist' (they should not indiscriminately favour the state) but adherents of fptp will say that to favour the big two parties is not to favour the state itself, merely those two parties. But this is wrong because the fptp system converts those two parties into something more important than they would otherwise be. The first-past-the-post system enshrines those two parties into something approximating to the state so the anarchist defence of fptp that the big two are not the state falls down and we can see that fptp favours the state, for the reason that it favours the big two.

First-past-the-post converts typical (but large) parties into something more than that and in fact makes them comparable to the state itself, which means that anti-fptp arguments are anti-state arguments.

Adherents of fptp typically claim that they are not being statist in their preference but this is wrong because they fail to see (are in denial of the truth) that fptp converts normal (anarchist) parties into elements of the state, so to protect the 'big two' is to protect the state.

Proportional representation is liberal

Democracy is good because it is liberal and the opposite of liberalism is criminality. We know that without an element of authoritarianism there is no crime so liberalism is the opposite of crime, which is always authoritarian. If something is not liberal then it is a crime.

So, as far as politics is concerned, we strive for liberalism. It is clear that democracy is always more liberal than its absence because it gives the people over whom the government seeks to rule, the power to replace their leaders with other ones. Democracy, being liberal, is not criminal and anything which stands in the way of democracy is a crime. We know (from earlier) that if democracy is good then pr is good but we can go further by saying that if democracy is liberal then pr is liberal too. And if something is liberal it is to be valued for not being criminal.

Proportional representation is more liberal than first-past-the-post because it is more democratic and democracy is liberal. To be liberal (in a political sense) is objectively good because the opposite involves authoritarianism and as a consequence possible criminality.

First past the post is plutocratic

We can see that democracy is good for the poor because it enables property rights to be determined not only by wealth but also popular opinion. The very rich are threatened by democracy because it means that in theory their wealth can be appropriated by the state, so true democracy is a threat to the rich. If there is a first-past-the-post system then the people do not have true democracy and the very rich are able to retain their wealth.

First-past-the-post is against democracy because it doesn't let the people take power from the establishment and this serves the rich. True democracy would enable the people to redress perceived economic injustices but the presence of the fptp system prevents this and makes sure that the rich retain their wealth.