In this passage we see the violent protest of a people who are propping up a futile belief system; the riot they incite is designed to inflate confidence in what they know deep inside to be untrue.
The more hollow the idol we follow the more we will find the need to prop it up. Diana could not possibly stand before the magnificence of the true God.
Idolatry is not great! Its promoters do so on false pretexts, and the idols themselves make empty promises.
Anything that we say we cannot live without is an idol to be turned away from. We should turn from idols to the living God.