The EZLN is an indigenous nat-lib movement, rejecting the idea that their lands can be controlled by the Mexican government. Many of the nations in the US and Canada had similarly fought with settlers and armies to maintain their lands, the reservation system is the residue of those conflicts, a suspended state of war.
If you have to say “we were successful until…”, how successful were you, really?
This can be said for any revolution, does the collapse of the USSR deny tested praxis of the Bolsheviks? The existing parties dominated by settlers have yet to provide a theory for revolution that moves beyond somehow changing the minds of the American workers, overwhelmingly labor aristocracy and reproducing with more labor from overseas than they put in. They haven't been able to change many minds; there are some 200k "Socialists" between the ML parties and the DSA, this is smaller than the number of Dine people and dwarfed by the number of Hawaiians who are building an alternative state in opposition to the American occupation. Dozens of millions of Americans straight up don't engage in electoral politics yet the Communists can't seem to make a dent there. The Fish Wars which saw collaboration with what would become the American Indian Movement and the Black Panthers got real wins in forcing the states to recognize treaty law. AIM and the Panthers attracted the most brutal state oppression, not disconnected from the general value American society assigns to black and indigenous bodies, and nothing of the sort has ever been directed at the CPUSA leadership as what befell the Panthers. The CPUSA fell into revisionism and tailed the Liberal Assimilationist line of the so-called "Black Bourgeoisie" which Frazier had proven was lying about the conditions of Black people in the US for the benefit of the Imperialist Settlers. This is not to say that amount of oppression is directly associated with revolutionary-ness, but that AIM and the BP clearly upset the settler order in a way in which Communist parties lead by settlers and white-dominated trade unions never could, and that opportunism for groups capable of upholding the settler order just doesn't exist for groups like AIM and the BP.
Indigenous protests have been at the vanguard of the environmental "movement" and indigenous lands have almost all of the biodiversity on the continent and indigenous nations are at the fore-front of conservation and environmental science. Black people are at the fore-front of politics surrounding police and have mobilized the largest protests in US history. We focus on black and indigenous people (with special attention towards Latinx and migrant workers given their super-exploitation) because these groups are most readily organized on an anti-Colonial basis. More than half of the settlers frankly live good and have little interest in unsettling the colonial order. This is why our direction needs to build up the most oppressed spectrum of workers in solidarity with those who do not fit in settler-society for one reason or another, push these community building movements into direct conflict with the settler order and stress the contradictions of settler-colonial Imperialism, like what the Palestinian Resistance is doing as we speak, and what the EFF is pushing to do in South Africa, the forms of our struggles differ by conditions but the dynamics are the same, a (class) war of national liberation for decolonization. We just won't see the level of organization from settlers in reaction required to defend themselves from us, our prediction is similar to that of what we are seeing in "Israel", the settlers will run and hide while their society collapses under its own contradictions. We will be there for the refugee settlers who wish to experience a different road.
Settlers as a book just shows actually existing history of the labor movement and choices made by settlers. Today we can see a deep lack in investigation of conditions from the "Communists" here. We will work with settlers who are sympathetic towards us but we will not rely on their assistance, with our without them we will fight.