First past the post is a stubborn problem

Only if the voters themselves abandon first-past-the-post by voting for the smaller parties will it ever get removed.

We can assume the members of the big two parties will remain loyal to fptp since it is so helpful to them... and if they decide that an alternate system is better then they become a supporter of another party (they have abandoned the big two).

The reason the first-past-the-post system is so resistant to argument is that it doesn't enable critics to emphasise their natural rights in the way that typical violations of our rights are vulnerable to. If we take the simple violation of natural rights which is physical assault the complainant can easily argue that they have a right to retaliate and that to do so will be an act of defence against aggression. Assault is aggression so it is easy to argue against. So too with government violations of our rights, let's start with taxation which Libertarians argue is an aggressive violation of the non-aggression principle. So too with drug prohibition, this is seen as aggressive and to argue against it is easy because we can claim that force used in retaliation is justified. And so we have established the principle that if retaliatory force is justified then it is easy to argue against a proposal. The problem (as far as rhetoric is concerned) when we come to the voting system is that the absence of a true democratic system is not aggression. It is not aggressive not to provide pr because the absence of something is never aggressive, by definition. And so fptp remains resistant to rhetorical arguments...

Since this is the case we can never convince adherents to fptp that it is wrong unless they come to the realisation themselves which means we can only wait for everyone else to realise the problem and abandon the big two. The parties themselves will not wake up and even if individual members of each party wake up this will not make a difference because the natural course of action in that situation would be to leave the party, as many have done.

First-past-the-post is a stubborn problem which is only remedied by large numbers of people abandoning the main parties, which is only achieved by each voter coming to the realisation that there is a problem.