Because no one rewards long-term efforts. You are rewarded for short-term goals and, at best, mid-term ones. In an abstract sense, customers reward you for long-term efforts, but this is something no one will put in an Excel spreadsheet with financial voodoo calculations, except when you are the sole owner of the business.
Could this perverse incentive be rectified in some way? Perhaps by offering much of the compensation in equity that they'd have to hold on to for decades?