Dr. Kramer describes one of the most wasteful reasons why EHRs and EMRs have such a limited life cycle. Other explanations include compatibility changes from mergers and acquisition, regulatory and data burdens which make systems obsolete, and, of course, performance issues when current systems don't perform or are not accepted as had been hoped.
One reason I never hear for replacing electronic health record systems, though, is from Moore's Law, the axiom named for Intel founder Gordon Moore which posits that computer speed and memory double every 18 months to make the former iterations of everything from core processors to digital cameras obsolete.
IT is and always will be a fluid and ongoing investment. Using a reliable system of interoperable electronic medical records is the single make-or-break operational evolution that has to happen in this decade for healthcare to have even the chance to reduce costs and improve care. There is a difference, however, between a sustained investment in a long-term "utility" and throwing capital at vaporous, "disposable" systems.