If you are done with the "undergrad level" of Popper and Kuhn it is worth reading Imre Lakatos's work on philosophy of science. It contains a moment where one realizes that research programs live or die by this "impact factor" and that this living or dying is a key part of the overall methodology of science. The gist is that science is actually participating in a survival-of-the-fittest evolution with certain foundational ideas as the "genes" which "reproduce". So scientific ideas are actually good or bad in no small part due to their ability to create further scientific research along similar lines. A low impact-factor therefore directly says "along this particularly important-to-science axis, this journal sucks."