Those are companies that had enormous PR disasters and had short-term stock losses. It didn't even have anything to do with boycotts.

The consumer collective-action economic effects of that boycott changed nothing. What did change things was the government action it triggered:

> Pressure increased across the country. The related civil suit was heard in federal district court and, on June 4, 1956, the court ruled in Browder v. Gayle (1956) that Alabama's racial segregation laws for buses were unconstitutional. As the state appealed the decision, the boycott continued. The case moved on to the United States Supreme Court. On November 13, 1956, the Supreme Court upheld the district court's ruling, ruling that segregation on public buses and transportation was against the law.

"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.