He was the Superfriend that everyone can relate to the most. Aquaman was too messed up to understand, and it takes hallucinogenics to get inside Zan and Jayna's head, but everyone knows someone like Samurai. A white American trying to assimilate someone else's culture. You might have had a white kid call you "homie" when he was selling you ice cream at the mall. You probably have a friend that went to Europe for a month and came back with a completely new dialect. They'd try to make sure you see them ordering baked beans for breakfast, and do their best to mention your apartment so they can call it a "flat."
Here's something else newly cosmopolitan people do after after they get back from their trip: if you give them a chance to talk, they'll relate any event or detail to the country they visited no matter how boring or unmentionable it is. For example, they might interrupt your cocktail party to say "These olives are dark green. When I was in France*, the olives were a much different color. I remember I ate an olive when I was riding the lift over there." And if you're honest, you might say back, "You seem different after your trip... Ever since you got back, it's like... it's like Europe gave you autism."
*Note: If you changed "France" to "Ancient Samurai Tradition," put your hair up in a bun, and pulled the collar of your shirt down to your waist, people would totally think you were Samurai.
Samurai never missed an opportunity to give his friends history lessons. It didn't matter if they were sinking in poisonous oatmeal or tied to electrified railroad tracks, he'd tell them exactly how the situation applied to the Way of the Samurai. Any time Samurai did anything, no matter how crazy it was, thousands of samurais before him had already written an instruction manual about it.
Say he's fighting Scarecrow, and Scarecrow fires a bird at him with his sinister Crow-Gun. Instead of ducking, Samurai would say "A samurai is trained to get out of the path of a charging bird by looking within to the innAARRGGGHHH!"
His way may get him hit in the face a lot, but at least El Dorado, Apache Chief, and the kids at home now have a working understanding of samurai tradition. Which seems to be giving a lot of speeches immediately followed by an ass-kicking. I don't know if samurai groups ever protested the show for misrepresented them as nude punching bags. They probably should have. Now that I think about it, perverts should have protested the show too for showing all people in spandex to be complete idiots.
Now I hope you have a better understanding of Samurai-- he's not really foreign, but he hopes you don't find that out. He tries to hide it by pretending to slip into his "native tongue" during a panic, but when he does it he has a midwestern accent and pronounces everything wrong. The saddest is when he ARE-EE-GOTT-O's the other Super Friends after they rescue him. And he needs rescuing almost as often as Aquaman. He's just as likely to walk into whirling blades or landmines as the rest of the Super Friends, only a little worse since he's always preoccupied about the next chance he'll get to slip in a fascinating fact about Japanese samurai techniques on bicycle brake repair.