See, syd, I disagree.
You've got bishops like Bruskewitz in Lincoln, who has welcomed the FSSP into his diocese, but still maintains the Novus Ordo according to the GIRM, celebrates the Novus Ordo himself, and things seem to work well there.
OTOH, you've got Mahoney in LA and many others, who would never bring in the FSSP, let alone establish a Tridentine Parish.
So, the bishops cannot be entrusted with this. They won't do it, the balance will never be achieved.
If I were a bishop, I would designate an FSSP parish or two, see how they work, then designate more, if need be. My reasons would be selfish, of course; I'd want to rid myself of the aggravation of the continued complaining from the Tridentine advocates.
But, not every bishop is open to this, and it doesn't appear that the Pope is going to force the issue.
For the vibrancy and unity of the Church, a Tridentine Rite is needed.
If you don't like the name, hell, you can have the name "Latin Rite," and let the Novus Ordo Rite be called the New Order Rite (or something else).
The never-ending wars on FR have convinced me that the Church needs a roadmap to deal with this, resulting in two separate "states," if you will.
And I'll admit it: the reason your solution won't work is because of recalcitrance on the Novus Ordo episcopal side.
I have to side with sinkspur on this one. You're largely right, but there is definitely an element within traditional circles which passionately desires to do away with the Novus Ordo. A Tridentine Rite would not cause them to cease those efforts.