What is the memory-safe subset of Java? Java is memory safe by definition. Sadly, the definition might not give people what they want, which is bug-free code.
High speed fiance is mostly done in Java and Haskell, because mistakes are expensive. (And yeah, it's one of the very few fields that Haskell enters the list.)
Grew up on C++ and the paradigm (& loved it), but then moved to interpreted for use cases.
I think the uncoolness of them is due to OOP methodology... programmers today seem to want to be easier to get moving, but then spend more time debugging OR the debugging has been "placed onto" DevOps / use of Cheap fast hardware. IMHO