Yes, make it entirely black and white so he has no real reason to do this connected to his own morals.

Even against a terrorist, what he did lacked morals and was purely out of revenge. Nico being a terrorist was Walker's justification for afterwards. In the end, he still didn't deserve the Captain America mantle if his use of the mantle was not going to be for heroics.

Also it would not have made any sense. He was seeing red regardless of the serum. It doesn't really affect your mental state.

I get that, it just It's so tiresome to discuss it with people who act like Walker didn't do anything wrong, that just because Nico was a terrorist he deserved that, even though that if heroes murder their enemies in cold blood after beating them then they're no better than them.

The Thing is that those people are still going to Say that Walker did was right even though if he did kill a innocent Man because it's not about Walker for them, It's about messing with Sam and saying that he's ain't Worthy to be Cap.

Yeah, it'd sadly be a ton of excuses no matter what. And would be just making the story incomprehensible just to expose these weirdos.

As Xandermcc pointed out, creating a more black-and-white scenario would create a far less interesting situation for Walker. Frankly, it seems pretty silly to complain about a plot point because it created a debate in the fandom. If anything, I would prefer characters to create discussion because that means that there was depth to their development in the narrative.