The inevitable abuse of power is the inherent flaw of all systems.
It really depends on the system. Ive had many supervisors who were high up on the ladder and were very warm and supportive. They used their "power" in a way that promoted their workers and the organizations. It really all depends how you use that power when you're in a position of authority. I dont work in the corporate/business world, so the abuse of power is less so in my profession, though Im sure it still exists on some level. Its also a matter of a degree, as well.
The other difference is that the abuse of a power by a cop can lead to death (cop blows a red light and hits a kid, or cop abuses their power and beats someone to death). This would rarely happen in other organizations that may involve more emotional abuse of workers.
Also, in many organizations, the ones who are abusing the power are higher ups (managers, CEO's, etc). Its not the little minion workers. However, with cops, many of them abuse power, even the ones on the low end of the totem pole. Hell, the cop I described was only a cop for one year. But he had that badge! You will hardly see a business man who has been working for 1 year abuse power in a major corporation. He'd be laughed at and fired.