There is no need for intermediate scripting language in UE4. Either be a programmer and learn C++, or be a designer and use BP (for which you still need to know how to make algorithms and such). I bet there is still a lot of stuff that could be exposed to BP, which I am sure will be exposed in time (AI stuff expose to BP is on the roadmap already).
Not saying C++ programmer can’t be an artist or animator or jack of all trades, but generally programmers are programmers and artists/designers are artists/designers. BP allows for artists/designers to create apps/games without programmers involved. Very good solution for indies.