Could it be that, being clueless, these high level managers are merely guessing and assuming that young workers are the only ones who can lead to profit growth?
Could it be that these high level managers fully expect these younger workers to lead and manage -- to do their jobs for them?
Of course, IBM is also destroying the skills and experience that customers are paying them to provide, but it's happy to get a short-term gain and ignore the long-term pain. The people in charge will have stashed away their millions and left before most of the ordure hits the rotating device.
Bear in mind that IBM's turnover today is less than it was in 2000, and it's had five or six years of annual decline. As a company, it's failing badly, so perhaps it's unrealistic for it plan for a future that might not happen.