Let's take a moment to appreciate the fact that the first two times Palpatine tries to turn Anakin against the Jedi, in Revenge of the Sith, Anakin’s first instinct is to stand by them.
In the script and the comic book adaptation, he takes it a step further and declares the Jedi are his family.
As shown here... he’s mastered the theory of the Jedi teachings. Rationally-speaking, he knows the Jedi are good and the Sith are evil.
Unfortunately, it takes discipline and commitment to put these teachings into practice. That’s the part Anakin struggles with.
This is partly because throughout his training, while the Jedi were trying to teach him things like discipline and emotional intelligence, Palpatine would tell Anakin that "he doesn’t need any guidance, he’s perfect just the way he is", enabling him.
Despite that failing, Anakin is still a trained Jedi and there is no scenario in which Anakin would just choose the Sith over the Jedi.
Which is why Palpatine switches his approach and stops framing the choice as a choice between the “Jedi or Sith” but rather a choice between “Jedi or Padmé”…
… and that makes Anakin’s defenses crumble.
But that rational part is still there. Deep down, Anakin knows the Jedi are good and what he’s doing is straight up evil.
So as he lies to Padmé, he lies to himself.
He focuses on the bad so it makes the killings easier to swallow.
"The Jedi were plotting a treasonous coup to overthrow the Republic. A strike force led by Mace Windu tried to assassinate the poor old defenseless Chancellor."
"They’re all gonna come for Anakin, now, so they need to be eliminated before they kill him."
"The Jedi are evil, they turned against him, and the galaxy is better off without them."
"He’s doing to end the war and bring peace to the galaxy, because it is better off with a strong leader who’ll put an end to the squabbling and indecisiveness of a corrupt Senate."
"He’s doing this for Padmé."
It’s all bullshit, he doesn’t actually believe that.
But it’s the only way to pacify that rational part inside of him, the valorous Jedi, the sweet little boy who keeps telling him to stop.
So this, right here...
... is Anakin repeating Palpatine's paper-thin rationalization to make himself feel like he's still in the right. Nothing more.
Lucas even says this directly to Hayden for motivation in these scenes:
And when you look at Anakin’s words on Mustafar, almost every single accusation he throws around are ones that are parroting Palpatine’s words, “Good is a point of view, Anakin.” “From my point of view, the Jedi are evil!” He doesn’t actually have any accusations with any specificity, just vague, “I should have known the Jedi were plotting to take over” and “I don’t fear the dark side”--again, things he got from Palpatine’s speech at the opera house--because it’s all justification for Anakin knowing he’s doing the wrong thing. He’s using Palpatine’s direct words, not even his own. He has to, because it’s the only way he can justify what he’s doing that has no rational justification.
