Good use of DI can help one write a more comprehensible, lighter, more flexible system, where each class is responsible for doing just one or two reasonably-scoped tasks. Unlike, say, an obsession with UML, DI is _not_ the hallmark of a crap-grade programmer. Nor is it all that simple, in the sense that it can transform your way of thinking about runtime configuration and object lifecycle management, and promotes a more flexible mindset.

That said, I absolutely despise autowiring and annotation-based DI...