Achei bastante interessante essa observação acho que esclarece muita coisa, do Mundo Web ao Mundo Java Corporativo interessante.
Por Rich Kroll
Comparing RoR to Spring directly is not a direct or easy comparison.
RoR focuses rather tightly on developing websites easily. RoR does a great job of making crafting pages, linking them together, and persisting data very easy. RoR was designed explicitly with web development in mind, and is a great tool for this. That said, when you need to do more “enterprise” development (messaging, integration, etc.), or have a need to do something that does not fit into the RoR conventions, you will feel some pain.
That said, Spring has many facets: Spring IoC, Spring AOP, SpringMVC, etc. that is aimed at solving a myriad of different development issues faced by developers. Spring has a very wide assortment of technologies that will ease most development challenges you will face.
To directly answer your question, it directly depends on your requirements. If you are developing simply database backed web applications, RoR will allow you to quickly and easily develop an application and is easier for the beginner to get started with. Spring on the other hand has a steeper learning curve and more configuration necessary, but gives you much more flexibility and power.
Once facet that I think is often missing from this type of discussion is the power of the community, tooling, and libraries available. Java/Spring is a mature platform with extensive community and tooling support, while Ruby/RoR has a great community, the tooling is still catching up IMO.