I think another problem is that certain high profile charities are almost untouchable. Channel 4's Despatches in, I think, 2010 found that the London Marathon charity paid only 25p in the £ to good causes and its highest paid employee (who they would not name) earned £250,000 - twice the amount of the highest paid employees of Oxfam and RSPCA. The London Marathon Charity, like all other charities, has to file accounts but discloses the absolute minimum amount of information required in relation to salaries and other expenses.
I can see jingle's point. A salary of around £100-120,000 does seem very high but it is much less than for comparably responsible positions in the commercial sector. Speaking personally, I gave up a very useful job in adult literacy teaching to return to legal secretarial work because I found it exhausting and demoralising to work just as hard for a fraction of the pay. Of course, I wasn't earning anything like the sorts of salaries we're talking about here, but the principle is the same. When people have families and mortgages to pay, can they always be as altruistic as they might like to be? And let's face it, these charity CEO salaries are a drop in the ocean compared with what bankers have earned for wrecking the economy.