I think there are a few causes that are superfluous - sort of 'fur coat and no knickers' - that receive millions in funding from the public, simply because they're a household name and they're very good at marketing or known for an event (Comic Relief, I'm looking at you).
However, from working many years in the third sector, what really irks me is the number of non-roles in charities. Long role titles and almost always in management; there are a lot of people doing nothing for their healthy pay packets (front line charity workers are often poorly paid in comparison). People happy to hide in the sector and hold their hands out without needing to give a rat's arse about the cause they work for. Maybe this isn't the case in your charity, before I get shouted down, but I've seen it a lot. Some cases could almost be considered fraud, in my eyes.
It annoys me because they're roles that appear to be necessary on paper, but this is rarely the case in practice (in one household name charity, my boss's boss spent all morning with his feet up on the desk reading the daily paper. He was on more than 40k 20 years ago). The sad outcome is that they drain money that could make a real difference to the beneficiaries or end service user.
I actually don't have a problem with the wages of charity CEOs, for a number of reasons - the responsibility on their shoulders is huge, and often life or death outcomes rest in their lap. It's middle management that are the leeches, in my experience.
Rant over. Apologies, I've gone off topic.