From the firm's point of view, the hope is that the company will reap a better image or media attention from philanthropy, so naturally they prefer to "invest" in attention-grabbing new issues or one-off high-profile events. To a business, it is a sign of ineffectiveness to spend five or ten years on the same thing.
站在企業立場，贊助公益希望回收形象或換取媒體曝光，自然偏好「投資」新的話題或短期專案，五年十年做同一件事，似乎太缺乏「績效」了？