Not-for-profit, charity, non-governmental organization (NGO) . . . most of the names emphasize what these organizations are NOT. And when we study .org websites, it's obvious that they differ from the clear value proposition offered by commercial websites. Typically, you visit sites because (a) you want some stuff they have and (b) you'll pay money to get it. Not so with non-profit sites.
Non-profits must clearly communicate their value proposition if they want to attract volunteers and online donations. Sadly, such communication is the sore point in the non-profit user experience.