As you all know, the PyStan license is GPL-3, while the Stan core is BSD. In some corporate environments this causes a number of issues, and means we can’t use Stan effectively. It also means we can’t use derived works like Prophet.
I understand that RStan does this because of how it uses (used?) the GPL Rcpp package (and that GPL is much more common in the R world). I’m not aware of any reason besides developer preference for PyStan not being available BSD, which is quite common in the python data science world (NumPy, Pandas, SciPy, Scikit-Learn, and Cython are all BSD or BSD compatible Apache or MIT). Would the Stan team (and particularly @ariddell, who seems to be the main contributor) be willing to consider a BSD compatible license for PyStan?
(n.b., 2014 thread here)