Euripides and Dionysus

I read chapter 12 of R. P. Winnington-Ingram's Euripides And Dionysus: An Interpretation of the Bacchae, which spends most of it's time on what The Bacchae isn't about, more-so than what is is. but is does say;

The play deals largely with the quality, value and implications of Dionysiac experience, which, when organised and consequently enhanced, creates a political problem. but which exists as an element in individual human experience.