I apparently failed to make my point. To informed people, that overhead is being funded by separate donations is clear enough. Uninformed people are developing a habit of thinking Watsi is a for profit business (and then making angry noises). It is my view that phrasing like "The idea of separating overhead from donations" exacerbates this source of noise.

"that overhead is being funded by separate donations is clear enough"... that's not always the case for all nonprofits.

Do you have a source for the thinking that people perceived Watsi as a for-profit business?

Mostly Paul Graham's twitter conversations and the occasional paranoid comment posted here.