The quick and easy answer is because if we don’t learn how to SPEAKOUT our species is doomed to go out without a Squeak.
And the longer answer –
Individuals need to notice the emergency of current world issues, which can be hindered by distractions or preoccupation.
They need to classify the status as an emergency, meaning to recognize what is really going on, and this can be hindered by pluralistic ignorance -when a group of people do not notice an emergency because those around them are simultaneously not noticing or reacting to the emergency: it is thus assumed there is no emergency-.
People need to take responsibility in the emergency. Studies show that the more people present at an emergency, the lower the chance is that someone will help. This is known as the bystander effect and creates a diffusion of responsibility, which leads the individuals to feeling less responsible for what is going on: “not my problem”. This means that a lone individual is far more likely to help you than that same person within a group.
The 4th step is to know what to do, and the 5th step is to do it. But, even after taking responsibility and knowing what to do, it is possible someone will not help due to social inhibition. This is where the social context, or social norms, prevent or dissuade helping in the situation.