I think what they did was fine. Actually, what I saw in the unused dialogue subtitle files from the PC version alluded to some darker things that the demons did...espcially in demon run foster homes. So if they were going to include that stuff, I'm glad they didn't.
DmC did nail the worry about the banks, world debt and how it could enslave people; the cult of celebrity and wanting to look good even using plastic surgery to do it, taking a shot at rality TV with that Devil has talent part, The Order being like Anonymous and Bob's prison for people who spoke out against demons. Actually what was alluded to in the demon prison was pretty brutal too.
Besides, I would think it is shocking to discover your drink is not only controlling you, but is also spiked with demon vomit.