As if the goal or intention were to approach UNIX's philosophy. UNIX is practically by definition decoupled. Integrated Development Environments are by definition integrated.
I spent years hating Java and embracing vim, but as I tried to shape my environment more, I grew increasingly frustrated. Finally, I was forced by necessity to use Eclipse and Maven with Java, and the lightbulb turned on for me.
Any language that takes 30-40% less code to do something for you is taking away some freedom. They're making convention easy but can make escaping it to be hard, or may slow down because of more dynamic-ness, or some other tradeoff. And there are many good tradeoffs to be had when creating programming languages, of course.
The deal with Java is that it is the pedant of languages. Half-answers and hand-waving to how objects interact (i.e. duck-typing) aren't good enough for it. This makes libraries or APIs very, very easy to reason about, because if it doesn't access to that information then that means that the library or API is broken or intentionally hiding those details from you. But on the other hand, it enforces a kind of light, but still present, agreement between classes on their relationships to each other.
The point at which your thoughts on IDE come into this is that because Java has a very rigid structure, it can make sweeping code changes at massive scale. This is something that, with shallower insight into the language, or without insight into the flow of code through a method (i.e. checking for dead code or invalid assignments), and so on, would take a massive number of man-hours to duplicate, or make use of the exact same code the IDEs themselves have written for the purpose (i.e. emacs and vim are capable of delegating certain functions to eclipse). Decoupling it in the UNIX way doesn't really make a whole lot of sense when everything is very interrelated in nature.
As well as generate, but given that some people think that if code can be generated, it should be done at runtime by the language instead, I don't want to argue this too hard in this reply. They're not wrong but they sure aren't right.