The story comes from the Yahoo contributor network, so it is a first-person "here is my story" article. Like you, Ken, I hope this type of thinking is not representative of how the average American handles a checkbook, but suspect it may be more common than we believe. What a sorry state of affairs.
There have been many lively discussions on this forum about our country's education system and the fact that many people can't do simple math without a calculator. The author of the article sounds like she can do the math ("Instead of spending around $750 a year on overdrafts, we can comfortably spend the $36 fee to keep the Visa") but may lack either the discipline or confidence to keep the check register updated.
If the person can't handle a checking account, then at least going to what amounts to cash-only (aside from the $36 annual expense for the Walmart VISA) is preferable. I shudder to think how they handle other financial obligations, though.