为什么在Servlet，JSP和轻量级DAO层工作时使用MVC框架？

I'm finding it difficult to embrace a Java MVC framework, when it looks as if Servlets, JSPs and a lightweight DAO will do just about everything you need it to do in order to decouple the controllers/views/models. For PHP I can see the necessity since there are no built in constructs like servlets, but do Java MVC frameworks really give you THAT much more?I'm finding it difficult to embrace a Java MVC