I would say Blueprint and C++ in Unreal are very good match - they complement each other very well. You done some stuff in C++, exposes some variables via blueprint and you can let just any junior programmer or artist to play around with it.
The non-existent of script is understandable, it is as if not enough differentiation between C++ are made but duplicate efforts are everywhere (you create functions in C++ and expose it for script). Blueprint and C++ are different enough they may not easily overlap in your workflow.
Also, it is not necessary for BP to eventually be converted to C++ - the multi threading nature of Unreal make slow blueprint not necessarily hogging the frame rate, but GPU in majority cases does it. In my case, the ‘game frame time’ is only about 1/5 of ‘gpu frame time’.