It's not stupid sir. It's smart. Neither of these guys are "retreads" so your argument is dubious. Between the two, Jones seems like the better guy. Single, film-room junkie, lives for football...actually was defensive coordinator at different points (except at NFL level). Parker has very little experience. And that matters at some point. The last thing the Cowboys need is a coordinator "learning on the job"...for a team that wants to win NOW.
I'm willing to give the man a chance but Jones was probably the better hire. From his interview notes..."future defensive mastermind". There was a "comfortability" factor for Jerry Jones reportedly. And when you keep making important decisions with comfort and not competence in mind, you continue to hamstring your team.