Indeed. Many Supreme Court upholdings are of the form "This isn't for us to decide, per separation of powers. Go bother Congress if you want this changed."
And I think that can be very problematic, especially when the SCOTUS makes incorrect assumptions about what laws are on the books, or that Congress will actually be able to act. In the Citizens United decision, a few justices believed that the disclosure requirements that would be needed were already in place, hence voting the way they did. In another, there was a Fair Debt Collection Practices Act case that found that debt collectors who purchase debt (arguably the very people the act was meant to regulate) were not covered under the act, and if Congress intended it, they should act to do it. This was in the last couple of years, so the amount of ignorance about how unwilling Congress is to act was astounding.
So what would you have instead? Less separation of powers? Laws decreed by a panel of nine, unelected justices to make up for what Congress "meant" but failed, or were too lazy, to do? If Congress won't do their damn jobs it's not for the Supreme Court to take up the slack; empowering them to do so will bring us down a dangerous road.
And Citizens United was about the right of corporations to issue private communications about candidates, not campaign finance. The Supremes couldn't have ruled except how they did without running afoul of the First Amendment. Given how easily hate speech proliferates, a strong right to free speech certainly warrants question. But changing things requires changing the Constitution -- much like the case with sensible gun regulations and the Second Amendment. I'm not sure what further public disclosure requirements you think would be necessary, but if Congress didn't pass them, it's not for the Court to slip them in as a rider on a decision.
