I think he is saying the types of companies that use Java are typically big enterprise shops. And it's true that in general they don't have proper career paths

I think he is saying the types of companies that use Java are typically big enterprise shops. And it's true that in general they don't have proper career paths for people who want to stay developers. Basically these kind of companies like to treat developers as a commodity. Developers aren't a commodity and good developers don't want to be treated as a commodity. In the java world this means good developers don't stick around. Companies that hire Clojure developers are frequently much more progressive about it (because if they weren't they wouldn't be using a language like clojure)