Considering that Blake’s original education and training was as an artist, it’s odd that someone who liked his poetry wouldn’t know he was an artist, as many of Blake’s works were first published with his illustrations. I’d tend to blame editions of Blake’s work that separate his two geniuses; art books only for the art, and anthologies of only his poems. The “Illuminated Books” tab on the Blake Archive site gives a list of his works originally published with his illustrations:
http://www.blakearchive.org/
