> While none of his objections had any legal merit, what exactly is scary in principle about using the law as it written to contest the results of an election?

But that's not what happened. What really happened was that Donald Trump and his lawyers repeatedly committed perjury and barratry by deliberately filing cases that were either false or meaningless.

Any petitioner acting in good faith needs their day in court.

There are already penalties in law for people who attempt to abuse the court system for their own benefit and these penalties need to be applied with maximum force to the Trump administration and their legal "professionals".