I was thinking laterally here [I think that I'm good at thinking laterally lol] and I wondered about how Alfred Hitchcock would have felt about LOST. That's when it occurred to me: the Source is a MacGuffin. A MacGuffin is a Hitchcock term used to describe a plot element that means a great deal to those involved with the story but seems really meaningless to the audience. The MacGuffin gives the characters motivation to struggle opposing forces even though the audience at large sees the element as worthless to the audience. For example, the Macguffin in "North by Northwest" is a statue filled with microfilm that MAY contain government secrets. It's important to all characters involved but the audience itself never learns the actual material the characters fight for. It is not important to us; it's only important because it matters to the characters.
The Source serves this purpose. It may seem meaningless to us because it almost is meaningless; it is meant to give the Island a special thing that needs the characters to protect. It is important to the characters and that gives it some significance to us. Part of LOST's problem was they tried to explain/justify the Macguffin. I don't believe it can be justified, only left for the characters to find value within it.
This is just a thought.