RPGMemes

The closest thing I found to an explanation in there is this:

The laws about resurrection spells were, as many laws in Cormyr, tortuous and specific, crafted in reaction to ten thousand crises no one wanted to repeat.

But it doesn't say what those crises are, or why a king would be so desperate to avoid them that they'd outlaw someone reviving them or ensure that their power is taken away if it does happen.