Not surprising that they are "popular" among young people in DRC. That unfortunate country is riven with conflict. Rich in resources, and therefore rich in rivals that want control of the resources. Net result: impoverished populace, horrendous fighting, dreadful attacks on inoffensive people who just want a quiet life.
DRC is a nominally Christian country, about 50/50 Protestant and Catholic, with a smattering of other religions. Clearly those denominations haven't brought peace, so why not turn to something that promises answers, powerful prayer, more harmony in the home [country]?
https://www.worldvision.org/disaster-relief-news-stories/drc-conflict-facts
But make no mistake. TWI is as a grain of sand in terms of percentage of population. Though sand in the machinery of war might not be a bad thing.