OP here, "why on earth" was in context to the talk. At said talk the person assumed the audience generally want r^2 to hold, but did not mention that r^2 should

OP here, "why on earth" was in context to the talk. At said talk the person assumed the audience generally want r^2 to hold, but did not mention that r^2 should preferably hold (for the reasons posted in other comments). In fact, the scope of the talk was much different. It mainly was to explain how we are looking for dark matter. Of course, this slightly diffirent topic is still very interesting. It happens to be confusing, though, for a person that may prefer theory extension over empirical extension (in their own research).