Oof, I thought he was alright. I think the writers trying to make us like him is a bullshit plan. Like if you want to make us hate him, just own it. His redemption arc also feels kind rushed tbh, like not bad, just could be better.
He's one of those characters that you love to hate, and I think he's well written for that.
To be fair, U.S. Agent in the comics is more along the lines of an anti-hero: right goals, wrong methods. Walker never felt inherently evil to me. Even when he killed the Flag Smasher in broad daylight (not his best moment as Captain America), what did you expect from someone who literally has the black American flag on the arm of their uniform? It literally means to show no mercy and take no prisoners.
John Walker was always a good guy, but his methods are what's messed up, not really his alignment as much. Heck, even Steve was at odds with the U.S. Government, and he had valid reason to dip when they offered the Sokovia Accords (unlike the comic version, the Mutant Registration Act, the Accords were far too vague, and also restricted their freedom as Avengers too much). Who made the government the standard for right and wrong?
Secondly, John's character arc is less about him going from good guy to bad guy to good guy again, and more about him finding the way he can better serve his country. Originally, it was through Afghanistan tours, then he became Captain America and had a bit of a fall arc when he fought Sam and Bucky. From there, in the final episode he chose doing what was right over the vengeance that resulted in him being stripped of his title to begin with. Then, he finally finds his place as the U.S. Agent, still technically a good guy, but his methods from that point on may be...shadier.
As for him being hated, I feel like people are gonna hate him regardless. He basically was elected behind Sam's back, treated Sam and Bucky like sidekicks, got blood on the shield, almost killed Sam, fought Sam and Bucky, snapped on the U.S. government... All that jazz. John Walker isn't too popular of a guy in universe or out, as people think he's tarnished Steve's legacy, thought he was replacing Steve, even going as far as to send him hate mail and death threats iirc... Either way, the entire time, I felt more sympathy for his character than Karli, tbh.
