But they still need to replace employees who retire and such.

EDIT: The reality behind the 'no time/energy to "train" me' is often that small companies do too little hiring for IT-type positions to support any sort of formal training, or even coherent documentation of their current stuff. (It may be quite different if you'd been hired as their junior-most bookkeeper or lathe operator.) And their tiny IT staff needs to be jack-of-all-trades problem-fixers - so if you need formal structures and training to get things done, then you're a poor fit anyway.