Of all the monsters that fill the nightmares of our folklore, none terrify more than werewolves, because they transform unexpectedly from the familiar into horrors. For these, one seeks bullets of silver that can magically lay them to rest. - Frederick P. Brooks, Jr
I think people considering the switch to a new lang need to read No Silver Bullet, from those considering COBOL to those considering Rails or CL.
At the risk of misinterpreting what you're getting at: the lesson to take from NSB is not "Don't switch languages" or "Switching languages is ineffective".
The lesson is: "Software development is inherently difficult; don't expect that to change just because you switch to a better language."
Brooks readily embraces and promotes the idea that better languages are vitally important, to strip away complexity that isn't strictly necessary for the already sufficiently complex task of building large software systems.
I think people considering the switch to a new lang need to read No Silver Bullet, from those considering COBOL to those considering Rails or CL.