When you want to get things done, you can do it yourself or you can get someone else to do it for you. Within many Open Source or Open Content projects you can donate your programming, your content and your money. When you are a programmer or an editor, you can choose what to develop, what to edit, because you are a volunteer. Nobody can tell you what to do. When you volunteer to give money, there is no such luck. You can give, you may be thanked, and that is it.
Unless of course you are a big time donor. When you give a sufficient amount of money and the purpose for this money fits within the aims of the organisation you give it to, you can determine what the money is spend on. This is not an option for small time donors.
Many small projects have been identified that need doing, projects that do not get done because they do not have priority or because nobody volunteers to do them. For such projects a specification can be made and a cost estimate can be given. These can be published and donations for these projects can be solicited. When enough people have contributed funding for a project, it can be executed.
For the complete policy read; Donations, putting your money where your mouth is.