system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Why does everyone hate the Separatists?

Why do they? I mean, they just want to secede from big, sickly, bloated mass of corruption and money known as the Republic, which is understandable enough. They just want to do things their own way. 

But now when Jedi, the so-called 'peacekeepers' of the Galaxy, decide to attack and murder innocent Separatists all throughout the Galaxy with their clone soldiers, the Republic spins it as a 'necessary measure' to restore peace to the Galaxy. 

Wake up nerfpeople!
gpt
Because each world that 'decides' to secede  brings with it a whole lot of people who don't.

Notice that the Separatists aren't fielding armies of dissatisfied citizens who want a chance at a better life. The architects of this secession are the Trade Federation and the Banking Clans, who have literally built robot armies to serve them. A look at the run-up helps makes the reasons why clear.

This all started with Naboo, where the Trade Federation invaded a planet to enforce their economic agenda. [OOC: Imagine if Exxon literally invaded Nigeria to overthrow the government because they stopped letting them extract oil.] They declared war, incarcerated civilians, assaulted natives, lied to the Senate about it, and then claim, "Oh, no, we were avoiding the corruption of the Republic!" once they were caught? Bantha-fucking-poodoo.

Snap forward a few years. The bosses of the Trade Federation spent a few years on a resort prison planet (This is actually pretty obvious corruption, and Naboo held more than a few protests when Nute Gunray got out in 5-8 for model behavior). However, their profit margin has been seriously impeded because of the whole "invaded a planet" debacle, and they are hurting. So, they hook up with other dissatisfied oligarchs and economic powerhouses. We're talking Mid Rim dictators, tibanna cartels, more than a few 'legitimate immigration specialists' who are all feeling the hurt of a bloated bureaucracy that moves ponderously but will come down like the wrath of the Force on anybody who steps too far out of line. None of these guys want the Jedi showing up on their doorstep because one too many of their ships missed a customs checkpoint. They are considering some form of mega-cartel or economic confederacy, when a former Jedi named Dooku appears. He points them towards the industrious Geonosians, who are more than willing to finance an army for the right price. He also talks eloquently about how much better off they would all be if they were part of a new government, one without all of these pesky interplanetary regs. A Confederacy of Independent Systems, if you will.

So, they meet on Geonosis to discuss their plans and formalize their Charter of Secession, when a pair of jedi and the Senator from Naboo show up. Now, somehow everything got a little bit out of hand and through a series of mishaps, all three wind up slated for execution for violations of Geonosian law. However, under a new addition to Republic Law the Jedi are permitted to conduct operations vital to the security of the Republic or the Jedi, and so when Masters Yoda and Windu arrive with a few hundred thousand of Palpatine's new military forces to rescue the Jedi and senator, the Republic views it as a perfectly legal rescue operation. The Separatist political movement, however, is fairly certain that this enormous army is here to nip their rebellion before it can ever get off the ground. (Remember, Palpatine just got these powers because the Senate was worried by a huge number of powerful factions with dubious moral codes chatting in back rooms)

So, after shit goes down on Geonosis, the Seps have to mobilize quickly, lest their movement wind up DOA, and the Republic observes that there was an enormous army on Geonosis that seemed a little to well-equipped for the 'private security forces' they were registered as. (general rule of thumb is that most battle tanks fall outside of the PSF umbrella).

Both sides are reasonably certain that war just broke out, and so when Palpatine dispatches clone forces to protect key worlds, most of the citizens are happy to see them. Meanwhile, Dooku and Sidious are directing Separatist forces to take key world quickly to stabilize their fledgling insurrection. Coincidentally, this leads to several worlds being the site of bloody and protracted battles, which hardens the citizens of the Republic against the Seps. The average Togruta on the street knows that the Trade Federation is always up to no good, and this time they've gone way too far.

As for the Separatist citizens, there really aren't many. Not a whole lot of well-educated or empowered populations wanted out of the Republic, because they recognized that rationally even a bloated Republic was better than no Republic. There are some worlds with dictators who tell their people that they are being protected from the evil Republic by the brave droids, but even then they don't want their people marching off to fight, to see how the evil Republic actually treats its citizens.

In short, the Seps don't have a whole lot of people actually yearning to throw off the yoke of the Republic. Just a few really powerful ones. Why do you think killing the leaders literally ends the war overnight?