what is the importance of speaking your mind?
It depends on your mindset. Some have power needs, some have attention needs, some have emotional needs to hear themselves, and some have mouths that just seem to be connected to a Duracell battery.
One can not make the changes in society that are needed unless one is willing to put themselves on the line by speaking up. Passivity in the face of needed change is being part of the problem. True, speaking up puts one in the line of fire from those who disagree, but change can be worth the risk. We became a nation because a bunch of people risked speaking out.