To most of those that believe that the world is flat, it is more a joke. A reason for a party here and there. After all Newfoundland is one of the corners of the world, and who loves a party more than a Newfie?
This issue isn't about believing stupid crazy and idiotic things, it isn't about the issues discussed. What it is about, is humankind's ability to disregard reality, and believe blindly in what they are told to do. This exists as a genetic predisposition, because of issues like: The kid who listens to his mother not to go swimming in the river doesn't get eaten by crocodiles. The child that listens to his father about not jumping off a cliff doesn't go smush. And they don't have to work by trial and error for this to emerge. This is what is called memetic driving of the gene pool.
The problem is, that we have gone to the point where we will believe ANYTHING, literally ANYTHING we are told, if it is told to us by a person in high enough authority, in the right way.
As time has gone by, more and more of humanity has left this idiocy behind, science has shown beliefs like flat earth, intelligent design, special creation to be what they are, ignorance and intellectual laziness.
But the problem isn't so much solved by just waiting until people go away, as soon as they do, some other issue that has been replaced by science will take it's place.
These people actually, in a way, serve a purpose to science (the concept of science, not the establishment we call science though) The force rational thinkers to constantly examine the issues, which in turn causes them to get better understandings of the reality of the issue. They in effect drive science further, to more concise theories. If no one questioned evolution, would there have been as many anthropological and archeological digs in Ethiopia? No.
These crack pots keep us with a constant reminder that we ourselves must not fall victim to that which they have done themselves. We cannot let science become a religion, whereby the "accepted idea of the time" is biblical.