Oswald's claim of innocence means either: A) he was really just a patsy or B) he wasn't motivated by ideology. Something else motivated him.
Now that’s a gigantic leap. The Centennial Olympic Park bomber was a radical who didn’t claim responsibly or plead guilty until over 5-years after the bombing. And even after he was apprehended he waited until his attorney came up with a plea bargain that kept him from being sentenced to death.
So, LHO’s claim doesn’t necessarily mean what you think it means...
The Olympic Park Bomber may be the rare exception. I don't know enough about that case.
If you're arguing that Oswald was motivated by pro-Castro/Communist ideology, then his refusal to claim responsibility does go against the pattern of terrorists or killers who are motivated by ideology.
It seems that you're suggesting that Oswald was radicalized by Communist propaganda and a die hard believer.
Generally, people who commit violence for political motives claim responsibility for their actions. Sometimes they leave behind a manifesto.
FWIW, I think Oswald was prepared to claim responsibility for shooting Gen. Walker if he succeeded and got caught. Hence the backyard photos and the "Hunter of Fascists" stuff.
Oswald even mentioned Walker in one of the letters he wrote to his cousin in 1963.
Unlike the Walker example, Oswald left behind no pattern of animosity or disagreement with Kennedy. The Warren Commission found no evidence that he disliked Kennedy.
It doesn't appear that the hostilities between the US and Cuba from 1961 to 1963 angered Oswald enough for him to say anything negative about JFK. But he said plenty of negative things about Walker. And I believe it was Walker's Reactionary rhetoric on de-Segregation that angered Oswald, not Walker's rhetoric on Cuba.