Even during SNL's salad days I didn't think lines like 'Jane you ignorant slut' was funny. But because the show was so popular I felt like there was something wrong with me.
Not on its own. But the skit itself was a parody of those point/counterpoint exchanges on some news programs which, on occasion, got nasty. In that context, the line was, if not laugh out loud funny, amusing.
I confess I absolutely loved the first few years of SNL. The cast and the dialogue were brilliant. Later years and succeeding cast members -- not so much. I keep waiting for SNL to die out, but now with Alec Baldwin as Trump, the show has come to life again.