Help!/Why the "no charity works" rule?

I am quite aware of the long-standing policy on this Wiki not to cover charity works. Not just not to make them valid sources, but the policy against even acknowledging their existence.

First, I am given to understand that it started because of the licensing issues, but… why do we care? We aren't the BBC, nor are we copyright lawyers. This kind of puzzles me.

But furthermore, and this is the real kicker, there was, I found while strolling through the Matrix Archives, a decision that the "no charity" rule would apply even when it's not that the copyright holders let someone else use their property for charity, but instead that the actual holder of the copyrights made a charity story with that copyrighted element.

There I frankly don't understand the problem. If the reason for the interdiction of most charity publications is that they're not properly licensed, why would charity publications where there is no wonky licensing also get roped in?