The MLs I know don't believe in a dictatorship [i.e. rule without constraint] of a party, but the dictatorship of the proletariat, i.e. the rule without constraint of the working class over the bourgeoisie, something approaching genuine democracy instead of the truncated version slanted towards capitalists that was deliberately created by people like America's Founders. Republicanism (representation with some day-to-day autonomy given to the representatives) is still logistically necessary for large democracies, but prioritizing the votes of large landholders is not.

Beyond that, I still haven't heard a very compelling argument for the use of having multiple parties at the top level (the PRC has many parties, though they are excluded from high office). I will not slander you as necessarily supporting the American system, but we can use it as a comparison point: In America, the power of two parties is mostly used as a negation of democracy, and we see this within the Democratic Party every election cycle. Aside from internal chicanery, there are routinely these bizarre arguments about "electability" used to undermine popular candidates and push a centrist to the nomination, even when that centrist has no hope of winning the general election (see Kerry in 2004). Even if this centrist is able to win (see Biden in 2020), his policy agenda is clearly deeply out of step with most Americans (would veto M4A, would veto pot legalization, constantly capitulates to Republicans, etc.). These occurrences aren't by accident, they are the modern system working as intended.

If people have differences in ideology, that doesn't seem like it really needs its own party when they can be hashed out within a single party and thereby remove a level of formalistic bullshit manipulating the terms of the disagreement (see above). There have been massive swings in the policy put forward by the CPC for just this reason, as various wings grew more or less favorable. It's been much more varied in policy than many multi-party states in liberal republics, which I venture is because of the above along with the more general issue of those republics being owned by capitalists.

Now, I'm not asking you to agree with this position or to even refute it (though you are welcome to). What I am interested in is why you would think that someone with the ideas described above is unworthy of conversation about political ideas, as you put it?