If you're actually casting cures, refreshes, and hastes where needed, your overall damage is going to take an epic shit.

Most Red Mages who put a sword on choose to ignore those responsibilities in order to deal more melee damage, which I'm sure we can agree isn't exactly top of the line even under the best conditions.

You're going to have to realize that most melee Red Mages are epic shit, and whenever you say that Red Mage can still cure from the front lines it's something that you'll have to live up to in practice. Yes, you can do it, but it takes a large toll on your total damage count if you're actually keeping up with all of your duties even as a secondary mage.

At that point, yes, on many things you will simply add more to your own workload by taking damage that you have to cure - sometimes, that can even lead to unnecessary deaths or damage because you're having to cure yourself where you could be curing a melee instead. Worse, a proper mage might have to heal you rather than healing a melee, a distinct waste of resources.

It's not just Red Mage that gets allocated to the sidelines in group play, it's any front line job that takes out more than it puts in by being up front. Anything that's safe for a Puppetmaster to engage is safe for a Red Mage to engage. That's about as simple as it can be put.

With that said, I hope that you actually keep stock of your support duties on the front line. You can sit here and preach all you want about how being in sword range doesn't stop you from casting, but it means very little if you don't actually cast. And yes, contrary to the vitriol you spew all over these forums, Red Mages do cast more than Cure 4 and Dia 3. Of course, you wouldn't have access to a good deal of spells with Ninja or, heaven forbid, Dark Knight sub, so you're automatically less useful there. Or did you forget the part where everything worth fighting slams every status effect in the game on you pretty much 24/7?