Okay, so I need some serious help. Can someone explain why anyone would want to use java spring beyond IoC? Half the developers I work with swing Spring around likes it's excaliber, yet when truly pressed why they like it they all say: "because of beans".

Spring is massive, so why just beans? The IoC pattern is extremely robust, so I'm sure there are other secrets to be learned. It has to have some other significant advantage.

I totally understand things like Jax-RS for REST endpoints. I don't think spring is needed for that to work, is it?