thanks for your response.
i don't think our standards of comedy in general differ that much. for example, i'm german so i'm just going to take the low hanging fruit: it's absolutely okay to make jokes about world war 2, the nazi regime and even the holocaust. i would even encourage people to do so more often. but context is important. for example, we have a famous comedian (or well, technically hes a caberet artist) in our country called serdar somuncu. one of his most known programs is literally reading and narrating adolf hitlers "mein kampf" (if thats something that interests you, amazon has a english version here). that is comedy that breaks and pushes taboos and conventions and is rightfully critically acclaimed. without going too much on a tangent, to provide further context, in germany you can't sell or buy an uncommented version of mein kampf. the punchline of that routine being that intonation and platform makes the difference between the ramblings of a madman and a dangerous ideology.
that is comedy in good taste, even if it is extremely dark. would the punchline be "lol they gassed the jews", it wouldn't just be bad taste and bad comedy in general, but very likely also very racist.
which is to say, i would actually agree with you, the basketball thing would make for a fantastic premise for a bit, but it is really down to the execution of it. if the punchline is "hAhA the players are black", it really wouldn't be all that great or in good taste. and thats essentially what trevor did there.