@kgw because it's a dumb claim that isn't really supported by the record, as the Supreme Court publishes its opinions that have not only diverse vote counts but also, and more importantly, stated reasoning that is not based on partisanship.
It's not more of an election issue because anyone who is informed knows that it's basically a conspiracy theory, basically just sensationalized nonsense to say that the court is plagued by partisan bias.
It's not an election issue because so many of us are better informed.