I think this is a reasonable expectation. I'm writing about the dot product and there is a geometric visualization for dot products, so it's fair to expect that. As I said in this comment (https://news.ycombinator.com/item?id=45802969) I focused on teaching the reader the bare minimum they would need to know to get to matrix multiplication.

I use illustrations for a lot of other things though. I use them to pace my posts, to call out things that are especially important, to reinforce written ideas with images, and to give the reader's eye a place to rest.

If you are looking for graphs, this video about the dot product from 3B1B may be more your speed: https://www.youtube.com/watch?v=LyGKycYT2v0