Another aspect to fiat law changes to consider: the sheer size of the law.
When a law is thousands of pages, and gives license to tens of thousands of pages of new regulations and references to other legislation, tweaks to the implementation then becomes almost necessary to get anywhere. In effect, when there is a flooding of law, the executive must get creative to implement, while the lawmakers get complacent to and condone encroachment on legislative power.
Bingo!