Why do you think monarchy has lasted( and is still here) for so long considering how flawed It is!?

Good question!

I think part of it has to do with hegemonic ideological power. To quote myself:

“Antonio Gramsci, the Italian Marxist theorist, coined the term “cultural hegemony” (although ideological hegemony also works) as the idea that the ruling class imposes the prevailing norms on the rest of society, which are then believed to be natural, inevitable, benevolent, etc. 

This makes revolution more difficult, because those oppressed by the system don’t yet see their suffering as injustice (as opposed to bad luck, or the will of God, etc.) and can’t imagine a world organized differently than it is. Hence why Gramsci argued that intellectual liberation was necessary for political liberation, or why E.P Thompson argued that class is a process of people creating a new world-view (rather than just a result of material forces). 

In a post a while back, I linked this idea to Steven Lukes’ idea of the three faces of power. Lukes talked about the three faces of power as decision-making power (formal state power), agenda-setting (the ability to decide what’s within the realm of legitimate debate, what is considered a “problem” and what isn’t), and ideological power (the ability to influence other people’s thinking, even when that thinking is against their interests). For example, we can see the third face of power in the fact that, even though Wat Tyler had seized London, he still felt that he needed King Richard to give the commons a charter of liberty and trusted that the King would keep his word that he would issue one and his word that Wat Tyler would not be harmed during a parlay.”

So if the dominant ideological framework of your culture is that kings are chosen by God and that rebellion against them is a sin, you need a lot of ideological lifting power to get people who are being actively oppressed by the monarchy to rise up against it. Hence why so many peasant rebellions from 1381 to the Bauernkrieg drew on religious justifications for rebellion, because the only thing above the king is God. 

But an even bigger ideological lift than that is trying to envision an alternative method for organizing political authority if one was actually to succeed in overthrowing the system, especially if there aren’t multiple ideological frameworks available to your culture/time. While monarchy might not be a very good system, like primogeniture it had the advantage of being relatively simple and having fairly universal acceptance. This made it superior than the alternative of chaotic civil war among rival nobles who no longer have any central authority to check them.

And even when there are other models, transitioning isn’t exactly easy, as we can see from the history of revolutions. Not only are other models usually denigrated by the existing culture. political systems require no small amount of learning. 

Why would Varys consider Kevan a good man considering he was the loyal underling of a cruel tyrant like Tywin?

Let’s examine the scene:

“Ser Kevan. Forgive me if you can. I bear you no ill will. This was not done from malice. It was for the realm. For the children…This pains me, my lord. You do not deserve to die alone on such a cold dark night. There are many like you, good men in service to bad causes…but you were threatening to undo all the queen’s good work, to reconcile Highgarden and Casterly Rock, bind the Faith to your little king, unite the Seven Kingdoms under Tommen’s rule.” 

As I’ve said before, Varys is an arch-utilitarian who doesn’t blink at the idea of building Utopia by spilling an ocean of blood and raising up a mountain of skulls. Hell, this is a man who mutilates children so that they can’t betray his secrets, who does it “for the children” – and he’s not insane or lying, he’s weighed the short-term costs in human lives versus the long-term gains of a complete remaking of the social order by enlightened despot. (Incidentally, this is why utilitarian revolutionaries are so dangerous, because their faith in the future justifies any atrocity.)

So how would someone like that look at Kevan? 

I don’t think Varys would object to Tywin’s methods as much as his goals and his frame of reference – Tywin was fighting for the glory of House Lannister rather than for the greater good; his efforts to keep the Seven Kingdoms together with war and war crimes would have been undone by Joffrey’s unstable tyranny or Tommen’s well-intentioned weakness or Cersei’s paranoia and misgovernment; and none of these people have the very precise training and worldview that would allow them to be a “perfect prince” who could make systemic change. Hence the “bad cause.”

At the same time, when Kevan took control, he didn’t act for his own benefit but to strengthen the crown and restore order in the capitol – by rebuilding the alliance between House Lannister and House Tyrell that gave the regime its political constituency and military hegemony, by ending the clash between Faith and Throne that was dividing the body politic and threatening further uprisings. Varys sees that as the actions of a “good man,” one who looks out “for the realm.”