Guwon was a threat to all of them because its not realistically possible that they can stick to his rules at all times. He made public executions mandatory at the smallest breaking of rules (as shown with a father stealing medicine so safe his child's life). In order to establish a just, democratic community he had to step down - this was the only way they saw this becoming reality, since he would not have left the village alone.
I agree with you. And if they felt miserable, they could've just left together and moved somewhere else. Instead, they killed Guwon and took over the town he had built, stocked with food, medicine, and weapons, and protected.
They owe him their lives, the town's infrastructures, and everything in it. They really are ungrateful.
After they are done with the Hounds, I wanna see how they'll survive. I look forward to see them die one by one.

High-key agreeing with her (female hound; I forgot her name). Because she's right. Guwon took them in, he fed them, he gave them shelter, and what they would just rebel against him? Sure he killed people but, isn't it crucial for them as well? Their situation in their world is already fucked up, I feel like this is one of the situations where they should just let go of emotions or idk...