Because the proper, approved, method for disposing of an American Flag which has become unserviceable (unsuitable for display) due to damage, wear, etc. is to burn it, in a proper ceremony with respect.
Not like this sh!thead in the story did, of course.
Google it, or check the American Legion site, or any of a number of sites dedicated to proper care and display of Old Glory.
US Flag Code, TITLE 4 > CHAPTER 1 > Sec. 8(k) states:
"The flag, when it is in such condition that it is no longer a fitting emblem for display, should be destroyed in a dignified way, preferably by burning"
I saw a video of unserviceable U.S. flags being destroyed in a discreet location away from public view.
The flags were not being burned, but rather cremated.