Dr. Seuss also grew up six human generations ago. Back when gay people were legally not-people and killed. Back when interracial marriage was illegal. Back when a black man could be lynched on the suspicion he was out of line. Back when the most distrusted group in the non-south were Catholics. Back when there was no food safety, no environmental protections, rampant poverty, and no public education.
Hell if we are going to do this to literature then there is just about EVERY book written more than a hundred years ago that ends up in the fire. Huck Finn (racism, bigotry). The Three Musketeers (vigilante justice). Romeo and Juliet (pedophilia). Lolita (yikes). Moby Dick (anti environment, no female characters, violence, racism). Frankenstein is a disturbing book about grave robbing and killing people that are different. Everything Steinbeck wrote. Hell, has anyone actually sat down and read the Bible? (hint, we call them atheists.) Name a classic story and we can all be shocked on our twitter feeds about how terrible said book is. We can go on and on and on and on. Or, and here is a radical idea, we teach these books. We encourage people to read them. And then we encourage discussions on how we have moved forward and no longer murder people left and right for being with the people they love. How justice should be as an ideal to strive for. How racist caricatures lead to wars where millions of people died. We learn from the past, get better, move forward or we kill our society. And part of that learning is reading the classics and seeing how far we have come and how far we still need to go.