Why do people need backers?

[Jorge10]

Ok I was reading Diablos post and Ed and Mason went over how backing might work. Here are a couple of questions I have.

Why do players need backers when it comes to paying for tourneys? Shouldnt they be able to back themselves since they are successful?

Also why do people back players who are unknown? Someone mentioned that "the grinder" was backed, but he was an unknown? When I first saw him play I assumed he won a seat online like everyone else that wins that is not a known pro. So why do people that are unknown get backing? Shouldnt they be good enough to pay for their own entries since they are obviously having great success at the cash games or smaller tourneys? Or at least be able to win a seat online?