It's pointing out that the equivalence of "simpler" with "more falsifiable" is not perfect. Nobody is suggesting that we just add silly details for the sake of

It's pointing out that the equivalence of "simpler" with "more falsifiable" is not perfect. Nobody is suggesting that we just add silly details for the sake of increasing falsifiability, but suppose two research groups independently arrived at those competing theories. Should we choose the simpler one or the more falsifiable one?