This doesn't show how many programmers work on "glue code" vs. "major applications" (which is why I asked if anyone has data on that), but it certainly shows that there is a lot of Python code out there that is not just "glue code". Bear in mind that it's not just the particular packages listed on that page, since many of them are frameworks; there are also plenty of "major applications" written in those frameworks.
(I am counting major websites using a web framework, major numerical applications using NumPy or SciPy, etc., as "major applications", btw, not "glue code". I suspect on re-reading this subthread that the poster I was originally responding to might differ with me on that point, but application logic is not "glue code" in my view.)
So where are your metrics?