I have to agree.. factories and IoC/DI in JS just seems like such alien overkill in the space. Yes, it's great when you need to create a testable system in a strongly typed world like .Net or Java, but in JS you can simple spike your module loader for unit testing your modules in certain conditions (proxyquire and the like).

Even in those platforms (.Net and Java) unit testing is such a miserable experience, and adds so much complexity it's easier to just skip unit testing in favor of simpler classes/methods and better integration tests.