"Essentially" is the operative word here. The Montgomery bus boycott was a small, geographically limited boycott at just the right time for an issue that was incredibly important personally to the boycotters. The boycotters were directly being very negatively affected by the bus segregation, thus they had much more of a personal stake than an upper-middle class individual who feels a pang of guilt after taking an Uber.

Go ahead, try to organize a boycott. I'll support it. I guarantee you it won't go anywhere, though.