None of this resistance was based on a desire for civil rights for blacks. It was based on a fear of losing money if racial segregation caused black customers to use public transportation less often than they would have in the absence of this affront.
Just as it was not necessary for an overwhelming majority of whites to demand racial segregation through the political system to bring it about, so it was not necessary for an overwhelming majority of blacks to stop riding the streetcars, buses and trains in order to provide incentives for the owners of these transportation systems to feel the loss of money if some blacks used public transportation less than they would have otherwise.
People who decry the fact that businesses are in business "just to make money" seldom understand the implications of what they are saying. You make money by doing what other people want, not what you want.
Black people's money was just as good as white people's money, even though that was not the case when it came to votes.
Initially, segregation meant that whites could not sit in the black section of a bus any more than blacks could sit in the white section. But whites who were forced to stand when there were still empty seats in the black section objected. That's when the rule was imposed that blacks had to give up their seats to whites.
Legal sophistries by judges "interpreted" the 14th Amendment's requirement of equal treatment out of existence. Judicial activism can go in any direction.
That's when Rosa Parks came in, after more than half a century of political chicanery and judicial fraud.