My problem with Skyrim is that it only really shows one side of the dragons, and that it is their very nature (@Paarthurnax) that causes them to be destructive, and that nature can only be checked by thousands of years of meditation.
Well that's how Paarthunax handled it, not every dragon in the past has done it in the same way, and some of them have been succesful. I guess it's kinda like a drug addict, some people quit cold turkey some people go to rehab, there are dozens of different rehab clinics with different programs and some might work for one and not the other. Paarth took his rehab way and stuck by it, but that doesn't mean every dragon should have to do the same.
I mean just look at the dragon that ends up following you (forgot his name) he isn't going around killing hundreds of people anymore, instead he seems rather peaceful and just kills when you ask him too. I don't know whether this a perminant or a temporary situation but it seems that dragons can overcome their "nature" in many ways, and perhaps not all are as bound by their nature as Paarth was/is.