Most Americans wouldn't consider Charlie Brown the "hero" of his strip, they would consider him a loser who gets what he deserves, and that's the joke. He isn't cool the way Snoopy is cool.
I think the article is correct that Americans don't feel sympathy for the underdog who doesn't overcome and succeed in the end so much as contempt, due to their inborn sense of entitlement and belief that failure is caused by a lack of moral fortitude and excess of laziness rather than systemic injustice and inequality.
I think the article is correct that Americans don't feel sympathy for the underdog who doesn't overcome and succeed in the end so much as contempt, due to their inborn sense of entitlement and belief that failure is caused by a lack of moral fortitude and excess of laziness rather than systemic injustice and inequality.