Rosa Parks was not asked to sit in the back of the bus. She was told to stand in the back of the bus. She wasn't even occupying a seat that a white person needed. The law essentially stated that not only could black people not sit with white people, they couldn't sit in the seat across from a white person either. When a white person came on and the bus driver told (IIRC) 3 black people stand up and move to the back, Rosa Parks refused. In part, because there was a perfectly open seat across the aisle.

The reason Rosa Parks changed the law wasn't really because she refused to move. It was because the law stated that a black person has to be moved to another seat - but because there were no other vacant seats for her to move to, the law couldn't be enforced properly. This is why civil rights attorneys jumped on the case and how they were able to change the law.

These fucking assholes conflating their 'discrimination" to Rosa Parks' is fucking disgusting.