I think what Larry is trying to say here, if I can broadly impose my interpretation on a paraphrasing, is that most philosophers of science call themselves scientists, but the people who choose to call themselves for some reason "philosophers of science" rather than "scientists" mostly have a niche community in which the only people who read what they write are the other people who think it's better to call themselves that instead of calling themselves scientists.
Larry is smart af, IMO, and his contribution to physics is about as great as you can make without getting the Nobel for it. If you make a list of living cosmologists who made an original prediction, and whose prediction was proven correct, then Larry is in that very, very short list. There is a longer but still short of people who had ideas that didn't pan out with experiments immediately. Larry came up with an idea, however, and then the other scientists went and made some measurements, and they showed that Larry's idea was just right.
