Many of the Western jihadists in ISIS are materialistic as hell. They post photos of golden AKs and pimped out SUVs, pool parties in some rich Arabs abandoned palace, etc. All alongside photos of them holding up dismembered heads.
I wouldn't say that the sort of Islam that ISIS practices is anti-imperial, anti-consumerist or even anti-Western. It is just straight up anti-human. Anybody who embraces sexuality, passion for knowledge, the idea of human worth, compassion for ones opponents... They are the enemy. These guys don't want humans to practice Islam, they want to replace humanity with a hollow shell, to be filled with whatever they please.