Economics is a subset of human, power relationships. That just speaks to the independence of methods and justice. One can use a perfectly good non-violent method for organizing a theft of the poor for the benefit of the rich, and doing it that way is clearly superior to doing it through violence.  It doesn't, however, change the injustice of the outcome or the need for people to combat it.  What Sharpe's (and others such as Alinsky's) writing has shown is that there are serious alternatives to violence for combating injustice, usually more effective alternatives, that can be employed by justice-minded people.