If you're still interested, here's an answer.
It's true that Jack Smurch has succeeded in flying solo over the Atlantic Ocean, something that no one has done before.
He's hot-tempered, foul-mouthed, disrespectful, egotistical, not particularly clean. His own mother is happy when he dies.
Through the character of Smurch, Thurber is poking fun at the way the media, in his times, tried to build up every hero as an absolutely perfect person. People like Charles Lindbergh (who really did fly solo over the Atlantic) were pictured in the media as being eventempered, respectful, modest, clean-living family men--in short, everything that Jack Smurch is not.
Although I love this story (together with just about everything else Thurber wrote) it is somewhat irrelevant today. The media today makes no attempt to portray its heroes as moral people. Just the opposite, it seems.