These racist caricatures have a long and ugly history, and they persist. They may seem mild to you, but to people who have to deal with racist caricatures every day of their lives, it's unpleasant. Not just having to explain to your children why they've been presented like that in this book targeted to them, but why all of the other children they know will have been exposed to the same images.
I don't think you intended to diminish that in your post, but I think it's worth taking note when you tell other people that they shouldn't be offended by something when you don't experience it.
Take a look at the images, and you can see why the publishers felt that they were better off without them. As for why eBay decided to glom onto that... that I can't say.