There are ways around it, if the terrorists are being aided and abetted by their families, are they not culpable too?
First, aiding and abetting is not the only rationale he provided for going after families. He specifically mentioned the fact that terrorists care about their family members, and that's justification for targeting them. That quote has been posted numerous times in this thread.
And in terms of "aiding and abetting", family status is irrelevant anyway. Although how you define that may matter. Technically, you could say that any wife that cooks dinner for her husband, or any kind that helps her do so, is "aiding and abetting". And no, we don't deliberately target and shoot those people. If that was enough, then the wives and kids of our military would be "legitimate" targets, and they most clearly are not.