It’s too bad the still-unresolved question of SpongeBob’s star turn for the We Are Family Foundation is getting mixed together with the PBS “Postcards for Buster” controversy, where arrogant ultraliberal Boston PBS station WGBH wanted to instruct the little children on accepting “Mom and Gillian.” In a brief turn on “Scarborough Country” last night, I could only explain for a second how subtle this dose of political correctness was for PBS, at least in comparison to the classic ancient example, the 1991 PBS/CPB/NEA-funded documentary “Tongues Untied.” For all of you young’ns who wouldn’t remember, you won’t believe it if you look here.