This is easier than you are making it. Comfort is a feeling of being comfortable. Love of comfort is enjoyment of that feeling.
You are probably confused because you don't see what's wrong with that. Given the context, I think the author thinks poorly of the pursuit of comfort because it is not courageous or interesting.
You can certainly remove the comma in red. Often comma usage is a matter of style, not grammar. This one serves only to give the reader a chance to stop and catch his breath, so to speak.
Student or Learner