Most violence in the world is motivated by moral sentiments
What is the opposing hypothesis here?  That violence happens in a morally neutral setting?  How would you define morally neutral?  Could you make a claim, for example, that a bank robber is motivated by morality (the bank robber believes that robbing the bank is the morally correct thing to do - to redistribute wealth to himself?)  Under what circumstances would that NOT be the case?  Would the bank robber have to say, "well I know this is wrong, but..." (and how would we characterize that "but..." as not just another dimension of morality)?