Which villain has more justifiable reasons to be one?#
Also, Baron Zemo from the comics. He sided against CA, that is true. But if he didn't, he could've further ruin his countries's reputation. He then wanted to kill CA so he could have revenge for his scars.
Loki (MCU)
Killmonger (MCU)
Kaecilius (MCU)
These are just some. Many Marvel villains have motives for them to be one.