Democracy was supposed to offer all the benefits of political change without any of the drawbacks of political violence, but it quickly organized into a machine that prevents political change, precisely because it shielded the elite from political violence.
Turns out, the benefits of political violence, or at least the credible threat thereof against the correct targets, materially outweigh its negatives.
To sum up, a people is far better off not being able to vote, as long as they collectively understand exactly who is responsible for their current condition and can organize violence against them.