The compiler is being worked on pretty heavily. The compiler is slow compared with what? Go? C? Generics are computationally expensive no matter what so the question boils down to generics vs not. Le_no_generics.maymay.jpig
It is not just about generics though, it is about using a constraint solver for type checking programs of a type system which is needlessly expressive.
Also, it is slow compared to almost everything, even C++. It has got better over the last 3 years, but most of that is pumping heuristics into the system.
