There’s a difference between the person and the job. The job has incentive structures, pre-existing momentum, designated authority levels. The job is part of a system. The job is connected to institutional structures. It’s easy to see this in political positions in government, for example – we all know about some people we like personally who “somehow” failed to fulfill their promise after they were elected. You’ll see the same thing happens in corporations and non-profits, too.
These realities make massive change difficult. We should not be surprised that passionate and decent people become ineffective in some jobs.
Breaking things and starting anew is often easier than reforming something from within. There are terrible problems with both approaches.