The point is the wiring: in cocoon.xconf, you only declare components, now how they should be wired together (this is handled by manager.lookup()). Declaring the full wiring leads to a bigger configuration and the knowledge of what wires need to be set up.
You remove the wiring from the code and move it into the configuration. Will this hold in practice when your application starts getting bigger? I think so, if you can factor it into coarse components (blocks) which are composed of fine-grained components.
That's why I like more construction injection for _required_ dependencies, as the container can check that it's able to pass non-null values for each of the constructor parameters. And you still can use setter injection for optional dependencies.
I tend to agree with you here.
Ugo
