While that is true, I'm curious what you would suggest as the remedy if, just before outgoing congresscritters were replaced by new ones, a bunch of them typed up a bill and gave it to the President, claiming that it had been approved by voice vote, and the President signed it? Who would have standing to challenge that, and by what means would such a challenge be conducted?
If the newly-seated Congress would have the authority to decide such a challenge by itself, with the legislation being struck down by a 50% vote in either house, then that would imply that Congress has far greater authority to repeal legislation than specified in the Constitution (which requires a majority of both houses, and presidential approval, or else a 2/3 majority in both houses). If invalidating the legislation would require a majority of both houses and presidential support, or a 2/3 majority in both houses without it, then some rogue congresscritters amounting to 1/3 of either house could conspire with the President to "pass" whatever legislation they wanted.
I really don't see any practical alternative to allowing some outside arbiter to act in such cases. True, that may seem to violate "separation of powers", but I would suggest that the Court has a duty to uphold the Constitution even when Congress does not.
I don't think I follow the events in your second paragraph. There was no constitutionally passed law to repeal, was there?
Your last para speaks to the frustration we conservatives constantly deal with. We wish to see a prosperous and happy republic and know we will have one if our Constitution is followed; the rats wish to tear it down and impose a utopia, which is certain to become a hell.
If the people want Utopia (hell), that is what we'll get.