The logic is rather basic. Can you disturb something that didn’t exist?
There are many English words and terms for people who make trouble. Some, like troublemaker, place the responsibility solely on the person. There is no trouble, so the troublemaker is creating trouble in fulfilling the role. Other words and terms, though, like protester or shit disturber, suggest there are reasons for that person to be creating trouble. Both types of troublemakers have their value and appropriate circumstances for being.
I coined this quote for situations where people have plausible causes to create trouble, like in protests. In such cases, if the protesters were troublemakers at all, there’s no way the blame should be all on them. There’s something going on that is not only bad, but bad enough, at least in their eyes, to be going through all efforts and taking all the risks, to protest. That’s not something little, and for that, I found the perfect English terms to describe such trouble, and the associated troublemakers. Those terms would be shit and shit disturber, respectively. The rest of the quote was just a point being made and a rebuttal, for effect and cause, respectively, to come out as you can’t be a shit disturber unless there was shit to disturb.