I love it when people think they are so important. First what I have to say is that it is up to the drivers discretion as to how many people are going to fit onto a bus. Yeah, we may have been on tighter ones but we are humans not sardines. If the driver did not feel it was safe to cram that many people onto a vehicle he is operating thus being in charge of those people's safety, then he should make his judgment based on how safe he feels doing it.
Secondly, I know everyone here is a hero and would have jumped in and saved the day, but really most people wouldn't these days. A situation like that is not something expected. Most people were probably in shock or too worried to jump in because they don't want to get entangled into any lawsuits of some sort. There is also what they call in Social Psychology, the bystander effect where with a bunch of people there everyone thinks someone else will do something so they don't think to act themselves. The less amount of people there the more likely someone would have jumped in. I am just theorizing though.
The security issue was a little ridiculous. If the video started midway through the altercation it still took like another 3 minutes for security to step in. Security should have been in there sooner. People get very irrational when it comes to waiting for buses and forget that it is basically a free service to them and they can get out of hand, so they should always have security close by there.