I honestly agree with SCOTUS on Texas’ lack of standing. The Constitution says that the legislatures of the states decide upon the method for selecting the electors sent to the EC. I absolutely think that the states where shenanigans occurred 100% ignored the method that their legislatures established for selecting their electors.
With that being said, those of us who support a strict reading of the Constitution are always complaining that judges should not be writing laws, but should strictly look at whether or not a law is in compliance with the Constitution. For that reason, I don’t think that one state has the standing to defend another state’s legislative intent. It is up to the people, the courts, and the legislature of the states where shenanigans occurred. If those systems fail, it is not the place for Texas to step in and fix it.
If a challenge to the election is to be settled in a Constitutional manner, that fix MUST come from within that state.