acting for political expedience? They are making heavily impactful, politically unpopular moves to correct what they believe to be long term errors buried in court precedent.
It's politically expedient for their goals, your post explains exactly why: they are hugely unpopular moves, if for any reason, because of the tremendous uncertainty they create in the law at large.
I don’t buy the idea that this creates uncertainty. When I read a statute I have a level of certainty as to what it means. When I read executive branch rules interpreting the statute I have a better understanding of what the executive intends to do, but - as they don’t write the law - it doesn’t provide much clarity as to what the statute actually means. The executive can and should continue to provide guidance about its intentions, but saying that the law is whatever the executive intends it to be is smoke.
Congress should get its Act together, but one group acting in responsible is not license for another group to act irresponsible.