Why is Coriolanus not very well known in the literary world?

Funny. The only reason I know anything at all about Shakespeare's Coriolanus is from my reading of Charlotte Bronte's third novel (after Jane Eyre), SHIRLEY (1849). There is a complete chapter in the novel called, "Coriolanus"; and it involves one of each of the two main heroines and heroes reading and discussing Shakespeare's play. I have yet to read the play, though I have a series of Shakespeare books in my library. I've only read Hamlet and Macbeth, and some of the poetry for high school and college. I could ask a similar question: Why isn't Charlotte Bronte's SHIRLEY very well-known in the literary world -- or the college-level English Literature class for that matter? The two heroines in the tale, Caroline Helstone and Shirley Keeldar are considered the contrasting traits of Jane Eyre split in two; while the two heroes, Robert and Louis Moore are refracting brothers, w/ differing characters.