So I have a strong distrust of the CIA, ever since I found out about MK ULTRA and Operation Gladios. I don't want to excuse their actions, and I don't really think they have a reason to exist now........BUT

You have to think of the mindset the led to the CIA, the CIA was an out growth of the OSS, which was basically just the CIA/MI6 for World War 2.

The men and women who were involved in the CIA had just seen a terrible world war that had led to a massacre of tens of millions of people, devastated the entire earth, and had seen humanity unleash the power of the sun on the face of the earth at will. To boot they were now facing down an ideological enemy that wanted to do the exact same thing to the Jews (see the Doctors Plot), and had the stated aim of destroying them and their way of life. Beyond that the entire US had been in a mindset of full mobilization, that the US needed to stand as a bastion of freedom, and liberty against the evil barbarism of Nazism (again the historicity of the point is debatable but it was the message).

So the people who were involved in the had lived through the storming of Omaha and been there on Iwo Jima, and so the idea was to create a clandestine, super powered organization that would be able to monitor things like the Nazis and assassinate their leaders before they came to power? Why, because no one alive wanted another world war and the devestation it had brought, not to mention the real risk that any significant military action would likely lead to literally the end of the world.

Now let's look at China, where the CIA had almost no intervention, they currently are conducting their third genocidal purge within their borders within the period of 80 years (The Great Leap Forward, the Cultural Revolution, the Uighers). To me this speaks to some extent that the fears of the founders were justified.

I believe that the men and women who founded the CIA and created it did so because they genuinely believed what they were doing was right, they knew they would have to make distasteful decision but they felt it was better than the alternatives that the faced. Now as the organization grew and as the original members started to be replaced, it became an organization obsessed with power brokering, using its "mission" to justify whatever it did, and became a tool used by powerful individuals who didn't like accountability.

I don't excuse the CIA, I think they should be held accountable for their actions, but I also believe that as long as we continue to think of them as one dimensional cartoonishly evil bond villians, we will never be able to make any progress towards putting them right.

EDIT:
Just to be clear I don't want to justify or exonerate the CIA, the biggest problem they faced, which is the same to all powerful and talented individuals and organizations is that of hubris and believing they knew better than anyone else. This led to a lot of terrible and despicable things, and atrocities, and then lead to efforts to contain the results of their actions, which led to a never ending cycle of fighting, destabilization, rebellions, etc., but again in the minds of the people making these decisions the things they did and the effects they had were better than the alternatives they considered. Not saying they were right, just that we can't attribute all of it to malice, as in many cases they believed they were basically dealing with the trolley problem.