Xerxes82
Absolutely true that no side is innocent on the show, but there are several key point that I thank we really don't get addressed well.
Marco is a faction leader in the Belt, so in Belter terms he is a legitimate political leader. Even if Earth and Mars wouldn't recognize it. Jules Pierre Mao is a private citizen (though one with exceptional power and means) and his actions had no backing by any government (even if he had a high ranking Earth official in his pocket). So right there is a significant difference between these two men. Now you could certainly argue that both men did what they did for what they believed to be legitimate reason.
But magnitude does matter. Eros easily the single largest horrific act by Mao, killed 200,000 Belters. The Belter population is between 50 - 150 million (Belters believe the larger number is accurate so I am going to use that). That means Mao in one horrific act killed 1/750th of the Belt. His actions while utterly horrific (Dr. Mengele would have loved it, its that sick) weren't ever designed to annihilate Belters as a society. Not even remotely close to it (It's far more statistically close to the atomic bombing of Hiroshima and Nagasaki in relation to the population of Japan). Now Mao was 100% successful in his plan for Eros. Marco attack on Earth (he also attacked Mars but we have almost no details on the damage there so not touching it), was not a success, his failure cause enough immediate death certainly tens of millions, and shortly hundreds of millions. This caused most of the Belt to jump to his cause, some grudgingly, but many of the factions eagerly. The ramifications of his attacks compounded by more and more attacks will end up killing roughly a 1/3 to 1/2 of the population on Earth. So between 10 and 15 billion. Thats magnitudes more people then have ever lived in the Belt. I firmly believe not only your actions but the intent you have in those actions are important. Mao's intent is to use 200,000 Belters as a medical experiment of lethal nature, but his intent wasn't to kill the Belt. Marcos intent is to kill the Earth, there is a difference.
Most of the hardship that Belters live by and see as only a Belter thing, also exists on Earth and in huge numbers. Lack of proper medical care, lack of jobs, lack of enough food, lack of clean water, lack of ability to influence change in the society. They do have free air. In fact most Belters I would assume were people who left Earth hoping to make a better life for themselves (see the US's California and Alaskan Gold Rushes, the rush to develop the west, ect).
Most of the oppression in the Belt isn't from Earth Government or Martian Government (there is some), but from the various Corporations that uses the resources of the Belt. Some have government contracts, but they aren't run by the government.
Yet almost all the hatred is directed at the governments of those two worlds. And if they hate the capitalism/ socialism mix that both use, they don't seem to try and change that model for their own practices. And in fact there are a lot of Earthers and Martians who also work and by extension live in the Belt. They do benefit from having a step up in promotions in companies, but that's the biggest perk they get.
Now Andersen Station assault in one of the biggest attacks on Belters (thousands are killed) and even then the Earth government (the Military side). Christen was surprised by this news (it predates her).So most of the oppression isn't in the form of eradication.
Now onto Drummer. Drummer states she isn't willing to agree to a position where anyone could override the vote of the Belt. I want you to really understand what that means. Originally its going to be an equal vote Mars, Earth, the Belt. Each government would have one vote. Drummer thanks that's crap. But to be in position where the Belt could never be overridden, means she wants a system where the Belt has final say. Period. On issues that aren't just Belter issues (if this was about forming a Belter government, or how they run their own government, then I could absolutely agree with Drummer. Mars and Earth mind your own damn business. But this isn't. This is an issue about the travel between gates, which is absolutely not just a Belter issue. Take the UN for example, 5 member states have veto power. But none of them have the ability to approve a measure. And as unfair as it is to have 5 out of all the countries have a veto ability, imagine how utterly unbalanced it would be if only one had the ability to approve or condemn a measure. That's what drummer is talking about.
And unlike Chrisjen (We know almost nothing about the Martian leader on the show) Drummer has only considered one Earther as someone she thanks should be treated fairly and that's Fred. There isn't an example of another. It's not Holden. Everything she has done for Holden or the Roci has been for another reason (Primarily Naomi). She's far, far, far less evolved on seeing others than Chrisjen has shown herself to become (and she's a stubborn thing certainly).
Again because this isn't a Belter business, organization or government why Holden feels it must be isn't very rational. After all does he know even one Belter who has risen in the ranks that hasn't been as bad (as the various corporations or governments that have prayed off the common worker) . They pray on their own, they use force to steal the livelihood of others, ect, ect. All the negative you thank of for big business or government. Certainly Drummer wouldn't be a rational pick. Outside of Fred she has refused to work freely or fairly with any inners. Even Holden and the Roci all her actions have been based on another reason (either self preservation or her feelings towards Naomi). And Drummer is seen by many as a puppet for the inners, so there is going to be significant Belters who don't trust her (outside of her being a pirate, and of course her long term work for Fred Johnson). Since many Martians and Earthers and Belters have worked in Space, and handled supplies or travel plans between stations, worlds, and outposts there has to be at one person who has a history of working fairly between the various races, and has some prior work history that would apply.