Corporations have no sense of altruism, nor willingness to adjust their behavior to protect future generations. Corporations pursue a single-minded goal, profit, and are typically legally prohibited from seeking other ends. There are no limits, natural or otherwise, to corporations' potential size. Because of their political power, they are able to define or at very least substantially affect, the civil and criminal regulations that define the boundaries of permissible behavior. Virtually no individual criminal has such abilities.
Corporations can combine with each other, into bigger and more powerful entities.
Corporations can divide themselves, shedding subsidiaries or affiliates that are controversial, have brought them negative publicity or pose liability threats. These unique attributes give corporations extraordinary power, and makes the challenge of checking their power all the more difficult. The institutions are much more powerful than individuals, which makes all the more frightening their single-minded profit maximizing efforts. Corporations have no conscience, or has been famously said, no soul. As a result, they exercise little self-restraint.