A couple reasons:

1. Most people are not emotionally invested in their job, the way they are with their identity.
2. People are afraid that demonstrating will either cost them their job directly, or move them to the front of the line for the next 'layoffs’
3. Income inequality causes infighting.
4. Small Business owners are often the first group to feel pain from workers rights, and major corps are last.
5. Lobbiests, politicians, and major (social) media networks working together to suppress the movement.

There are other reasons too, and none of them are ‘good’ reasons, but they are all realities.