I can certainly agree with many of the 
     criticisms. However, in my experience, Scala
     is still worth it

Considering the alternatives, C++ was and is still worth it. However because of its popularity, it prevented and still prevents other languages from gaining critical mass, making it the only game in town, with the sole exception being Obj-C, but that's only because Cocoa was designed for it and Apple doesn't mind a little technology lockin either.