There's also no law that requires the IRS to give LLCs flow through tax treatment...
The IRS could conform the treatment of LLCs to the way other limited liability entities are treated... as entities subject to taxation in their own right.
Maybe they could. I am uncertain whether they would need legislation to do so.
IMO that would arguably be the more correct option, but it would also remove the sort of information pool that can enable leakage or fishing expeditions the current law seems aimed to generate.