$300k salary, while definitely more than I will make this week, really isn't that off base. Many corporate CEO's make significantly more. If a CEO and a company's senior management bring value that warrants their pay, I say good for them.
The "non-profit" context of the organizations could be cited, but consider they are employees like many of us and have performance expectations that dictate their compensation just like many of us. The organization they work for is a charity, not them.
Do I agree that there are some CEO salaries that are just way out to lunch, like the ones making $xx millions a year? Sure, it feels inequitable, but that is for shareholders and stakeholders to sort out...
I guess at heart, I am a capitalist