Links on the blink - reprise

People are starting to tell me that the way out of smashing into the
brick wall at 60 miles and hour that the Links on the Blink discussion
was worrying about a week ago, is to take cascade or other frame relay
switches for the national service providers backbone topology and push
routers out to spoke and wheel hubs at the perimiters of the back bone
where traffic sent on the backbone at the data link layer (2) can pop out
and into the appropriate router for layer 3 routing to the final destination.

PSI and UUNET have apparently been following this strategy with their
backbones for some time. Netcom has also come on board. Its advocates
say that this combination can scale and avoid the 60 mile per hour brick
wall crash. Are they right? And if so why aren't sprint and MCI running
in this direction and away from purely router based networks as fast as
they can?

If they are why are they wrong? Where does this architecture fail? If
it fails.