I think, though, at this point, justice tourism is in fact actively detrimental.

The tourist narrative overrides any other voices, shifting the focus from important issues to non-important ones. Also, the tourists tend to turn on oppressed peoples with their frustrations rather quickly- consider the Prop 8 backlash against black people.

And, more importantly, it gets a lot of people feeling like they did something, so then they become resentful when asked to ACTUALLY do something.