Crowdsourcing and crowdfunding are built around many individuals coming together to make something happen.
But crowds don't make things, people do.
Terry and Sarah and Herbie, not the crowd.
When we say to a group, "everyone help me with this," it's easy to let someone else do it. And those asked can see the surplus, the wasted energy, the duplication implied with 'everyone'. If the crowd is assigned to help every person down on his luck, or to keep the city or the planet clean, well, that everyone doesn't have to be me.
Bobsourcing and Lisafunding, on the other hand, understand that a clear, 1:1:1 relationship between individual, project segment and organizer can change everything. Wikipedia thrives partly because the 5,000 core editors can each monitor certain articles. None of them are required to worry about all of Wikipedia, just their article.
One component, one person, one contribution, all urgent and necessary and vital.
When we rely on the crowd, we get deniability. The organizer doesn't have to ask anyone specificially, and the individual is easily off the hook. But sometimes, the hook is exactly what you want.