Lack of time
Usually I work with small projects and Java configuration and abstraction level are too high. Defining everything in Java is taking too much time. I am neither professional programmer nor Java developer, so I don’t really want to spend valuable time to dig Java.
Traditionally Java uses really complicated templates’ engines like Freemarker or Thymeleaf. They are really complicated with billions of functions, which I won’t ever use (for example) for a simple blog. As for me these engines have a really verbose syntax, some of them even produce ugly HTML markup. Sometimes I got feeling that vendors of such templates’ engines never have written real HTML themselves.
I know that Ruby is relatively slow language, but Java is really slow and takes too much resources at least at startup. For small projects it is really expensive. For bigger Enterprise stuff Java fits well.
I’ve loved Ruby’s syntax from the first moment I saw it. It is really straightforward and you shouldn’t care too much about abstraction level and concentrate more on a task.
Last time I really don’t like Java stuff.
I ♥ Ruby!