Having electricity doesn't "justify" anything. Nor does it detract from post apocalyptic - in fact, it adds to it. Having shoddy little pieces of old technology is what post apocalyptic is. Rather, not having it adds to a feel of fantasy instead. Having crude salvaged technology jury rigged to work with whatever you can find is what a post apocalyptic setting is. If you deny what a post apocalyptic setting of any technology, you are creating an oxymoron of a setting. If it were to be no high tech at all, it'd have to be more than a decade or two after, it'd have to be many centuries later. And even with that setting, it makes no sense as to why not just make a fantasy medieval setting in the first place.

But yeah, tribal for now, we need to build our way into salvaging the technology. That's why this idea would work when they eventually get farming in, which will probably be quite a while.