Their ideology is in their indigeneity. They do study western leftist currents, but don't see them as their own movement. Rather, they see the proletarian struggle (as colonizers with colonizer class interests) as something separate from their struggle against colonization by the mexican federal government. They welcome Mexicans to engage in their own struggle, but believe it will be a fundamentally different thing with different aims. Proletarians do not understand the EZLN's aims or ideology in such a way that a communist state would necessarily be compatible. The EZLN sees global communism as a noble goal to end imperialist hegemony, but they don't believe a proletarian communist state will automatically consider their interests in the same way they currently can manage under self governance. For them to integrate, respect would have to be earned.

While we are on the subject of rebellious indigenous peoples, a parenthesis would be in order: the Zapatistas believe that in Mexico recovery and defence of national sovereignty are part of the anti-liberal revolution. Paradoxically, the ZNLA finds itself accused of attempting to fragment the Mexican nation.

The reality is that the only forces that have spoken for separatism are the businessmen of the oil-rich state of Tabasco, and the Institutional Revolutionary Party members of parliament from Chiapas. The Zapatistas, for their part, think that it is necessary to defend the nation state in the face of globalisation, and that the attempts to break Mexico into fragments are being made by the government, and not by the just demands of the Indian peoples for autonomy. The ZNLA and the majority of the national indigenous movement want the Indian peoples not to separate from Mexico but to be recognised as an integral part of the country, with their own specificities. They also aspire to a Mexico which espouses democracy, freedom and justice. Whereas the ZNLA fights to defend national sovereignty, the Mexican Federal Army functions to protect a government which has destroyed the material bases of sovereignty and which has offered the country not only to large-scale foreign capital, but also to drug trafficking.

https://theanarchistlibrary.org/library/subcomandante-marcos-the-fourth-world-war-has-begun

Zapatistas have won the right to the word: to say what we want to, about what we want to, when we want to. And for this we do not have to consult with or ask permission from anyone. Not from Aznar, nor the king Juan Carlos, nor the judge Garzo’n, nor ETA.

We know that the Zapatistas don’t have a place in the (dis) agreement of the revolutionary and vanguard organizations of the world, or in the rearguard. This doesn’t make us feel bad. To the contrary, it satisfies us. We don’t grieve when we recognize that our ideas and proposals don’t have an eternal horizon, and that there are ideas and proposals better suited than ours. So we have renounced the role of vanguards and to obligate anyone to accept our thinking over another argument wouldn’t be the force of reason.

Our weapons are not used to impose ideas or ways of life, rather to defend a way of thinking and a way of seeing the world and relating to it, something that, even though it can learn a lot from other thoughts and ways of life, also has a lot to teach. We are not those who you have to demand respect from. It’s already been seen how we are a failure of “revolutionary vanguards” and so our respect wouldn’ t be useful for anything. Your people are those you have to win respect from. And “respect” is one thing; another very distinct thing is “fear”. We know you are angry because we haven’t taken you seriously, but it is not your fault. We don’t take anyone seriously, not even ourselves. Because whoever takes themselves seriously has stopped with the thought that their truth should be the truth for everyone and forever. And, sooner or later, they dedicate their force not so that their truth will be born, grow, be fruitful and die (because no earthly truth is absolute and eternal) rather they use it to kill everything that doesn’t agree with this truth.

https://theanarchistlibrary.org/library/subcomandante-marcos-i-shit-on-all-the-revolutionary-vanguards-of-this-planet