Video shows a comedian playing piano and singing to a sock. Am I missing an important point?

I've always wondered what narrative Bo is actually referring to here, I feel like the joke's maybe 25 years too late.

What's the classist big lie that kids are learning these days? I'm sure it varies around the nation, but the history I see young people learning now is generally pretty reconciliatory and balanced. Kids aren't learning "Columbus discovered America and had Thanksgiving at Plymouth Rock with the Indians" anymore, I like to think children's history education's grown some nuance since Bo went to school in the 90s.