The "worry" is not that this-or-that fantastical scenario might play out. It is that, as it turns out, the very mechanisms we use to measure group preferences simply cannot satisfy a list of very basic requirements. For example, the reason we do not use random drawings to determine who gets elected president is that we want the choice to "reflect" our preferences on the whole: but the result shows that this kind of "reflection" is probably not possible, and is always distorted in some fashion by the very procedures we adopt to make these decisions.