There is plenty of bad in the world and it is not about being helpful but rather practical while being helpful. If one is to interfere in to every single argument they see in the streets. Every single ill behaviour in the streets. Life is just simply not possible. Further more of the impossibility of "cleaning up" the world of bad people.
It's nice to imagine being a person who is like batman. Fighting for the weaker good people. However such a life is just not feasible and practical. Whereas people should instead, help those that are in their daily life instead. Helping a co-worker or a family member is much more feasible and realistic. Since their downfall can affect you.
It may seem selfish to just help those who are of relevance to you. However it is more sensible to do that. Instead of helping or speaking up against every single bad behaviour on streets. People fight and cuss all the time.
They can handle their own battles and it should be that way. They should be left to handle their own battles. If a person is getting say pushed around. It is not the place of a third party to budge in to defuse. Rather the most the third party should do is merely advise the person on how to react or handle such situation. Letting them handle their own battles. Even then one shouldn't be going to every single stranger and be advising them.
A batman type of character is nice to imagine and wish for. However it is very impractical and very much impossible to get rid of all the bad character in the world. So one should just focus on handling those that would affect them. Instead of every other person who aren't going to affect them.
If any one should only budge in if things are turning violent. People will have differing values. Some don't see wrong in insulting or quarrleing. Others do. They should be left to handle their own battles. Helping them may make you feel better. However they may come to rely on third party to always fight their battles for them.