That is clearly a matter only of Michigan election law, and Michigan's sole authority to regulate its elections is recognized in Article I, Section 2 of the Constitution.
All that Goldschmidt was allowed to rule was that there could be a due process violation IF the Michigan courts ruled the recount could proceed but it could not be completed in time. That is why he directed the recount to begin early -- just in case.
However, he has no authority over Michigan election law whatsoever, unless someone can prove to him that MI law violates equal protection, due process, or some other part of the US Constitution. No one has made that argument.
His ruling was not on the merits of Stein/Clinton/Soro's petition, which, let me repeat again, he has no authority whatsoever to rule on.
You are assuming people who abide by normal rules of jurisprudence. On the other hand, these folks are the same people who found "a right to privacy" in the U.S. Constitution and twisted that into the right to kill babies who had the unfortunate circumstance of not yet being born.
Yes, "No one has made that argument". Yet, we both know that there is a high probability that someone will. And at that point, "prove" becomes a wax nose (to use a figure of speech from theological terminology).