Firstly, not all human reasoning and subsequent behaviour is rational. Much is emotional.

Secondly, 'good' is a cultural prescription. All notions of good ARE subjective, however there is a cultural uniformity of the definition of 'good' born from group consensus and conformity.

Thirdly, if you choose to break the group consensus, you are likely to break said group's rule of law and therefore will face criminal proceedings.

Finally, activism is not based on an objective truth. An activist follows his subjective conviction in an attempt to change the status quo.