If Java is so great at solving these "simple" problems, then why do hugely complex frameworks like Spring exist?
The language features of Haskell that you mention can describe your "simple operations" symbolically, you then just need to write a few different interpreters, one for real services, one for testing etc. No dependency injection, aspect-oriented programming or AbstractSingletonProxyFactoryBeans needed.
You might feel that the complexity has just moved, but I'd much rather invest my time in solutions that are not ad-hoc.
Maybe. I've seen few Java apps that don't use Spring or something similar. The parent described a simple domain, arguing it is the common case, but nonfunctional requirements like testing typically make the problem more complex. So I dispute that Java is good enough for the common case and that nothing from Haskell would be beneficial. Incidentally, Java's leadership agrees.
