Creating an artificial system such as the ones which are today mainstream can have undesirable side-effects. What stops a group of indivudals (or bots for that matter) from injecting rule-breaking content into an otherwise-acceptable thread?

Soft-censorship and derailing is done on purpose to censor certain topics which go against the establishment status quo. Reddit is fertile with such examples. If someone is making a comment which does not bode well to those in power, it is common for the thread to be sunken with low-class behavior and baits in order to shut down valid discussion by forcing an emergence of rule-breaking content.

That is a far more greater threat.

How do you propose to mitigate that?