There are two ways of looking at Onoda. One is to admire his indomitable fighting spirit. (This is what the Japanese did upon his return in 1974.) The other way to view him is as a representative of a peculiarly Japanese form of fanaticism and craziness.
Onoda wasn't the only soldier who refused to give up. He was originally part of a group of four. One of the men surrendered to Filipino authorities in 1950, another was shot and killed in 1959, and another was killed by the police in 1972.
Another Japanese soldier hid out on Guam until 1972. And there were others who held out for years after the end of WWII.
Onoda and his men killed approximately 30 Filipinos after the war. Technically, this makes him a serial killer, which would be yet another way to view him. From a psychological viewpoint, though, he was the opposite of most serial killers.
What Onoda did by not surrendering was extremely admirable and extremely stupid at the same time. His never-say-die spirit and resourcefulness in wresting a living from the jungle showed a tenacity most people couldn't dream of. At the same time, you have to conclude that his actions were not those of a reasonable man.
I'm half-Japanese, and I see this fanaticism -- and stupidity -- in myself. For instance, this blog: I've now written over 1600 posts since 2008. Why? I don't get paid for it, and the blog averages only 600 readers a day, which doesn't compare to some of the more prominent blogs. It seems pointless, but I've stuck with it anyway.
I'm almost 60, and still swim competitively. I took the sport up at age 14, and have never given it up. I could talk about the health benefits that come from exercising, or the camaraderie of masters swimming, but the truth is, even without those things, I'd still swim. It's another pointless, profitless activity. So why do I do it?
Because I'm an obsessive half-Japanese.
It's not much of an explanation, but it's the best I can come up with.