I don't think you can call tune-ups routine. Granted, I've personally never have scheduled a routine tune-up before but I have a tendency to go in every 6-12 months. Your body finds it's own routine, mine needs a good IV kick every so often. When I was younger it was a year or so between tune-ups. My average is now around 8 months or so.
As far as routine doctors, I had one doctor who was really pushing a change; that everyone was admitted routinely every 6 months. So maybe a routine tune up is a good thing, personally had never had anything 'routine'. =) Hope this helps.