if you are happy with a programming language/framework/library/etc and you get your things done, there is clearly no obligation to look at other stuff.
If you are not happy, you might look into alternatives...
Why Civilian?
Our motivation: it was fun todo and it does work for us.
Your motivation?
Happy with JAX/RS, Spring MVC etc? Just stick to what is working for you.
If not take a look (but you did that already, so thanks for that).
