Making rules sounds awfully like legislation, which is a job for the legislature rather than the executive. Arguably, the executive can only regulate the executive, and Congress has to pass laws which apply to the populace at large.
That’s certainly not the way things have been run for a long time, but it doesn’t seem irrational to argue that’s the proper constitutional structure.
> Making rules sounds awfully like legislation, which is a job for the legislature rather than the executive.
Good thing Congress establishes independent agencies then. Their entire point is to receive rule making delegated to them by Congress.
The legislature is well within its rights to delegate rulemaking authority. (I recognize that non-delegation is a live debate, but I think it's a silly one.) But the executive has to make those rules within the bounds of the delegated authority.