What was it's accuracy?Anything within 15 miles? Useless for naught but killing women and children, unless they could have improved upon that
It has been pretty well established that the Germans were not alone in killing women and children with fairly inaccurate targeting techniques -- that is, when the women and children were not actually the targets, which they often were.
This site claims that, had it not been for the British disinformation campaign about where the rockets were hitting, they would have acheived a hit radius of 6km. If your goal is to kill civilians, that's close enough.
Depending on your goal, the rocket makes sense. Develop a payload large enough (e.g. nukes), and they are your best bet that the payload will be delivered.
My basic point was that the whole "strategically useless" and "waste of resources" arguments are fine with the benefit of hindsight. But in the moment, there were certainly reasons to go that path beyond the cliche' "delusional nazi" position.