When you take into account the media many of those BBS plants are in as well as the generally lousy care instructions provided, by the time they're done blooming the roots are often so far gone that a great deal of tlc may be required to nurse them back to health. Not surprising that many folks don't want to fool with them at that point. Then too, producers in many of the asian countries can mass produce them (particularly phals) so cheaply that as a disposable plant they are cheaper than buying cut flowers.
Poinsettas are disposable plants for me. While I enjoy their bright colors, they are too much trouble to rebloom the following year.