Never has it been said that boycotting in contingent on human right violations. Having been involved in human right awareness and activities, I can assure you of that.
Great example of a boycott that had no human rights connection, but was in every way right. A local nurses union was close to a walkout of local hospitals because those with authority were essntially taking advantage of the need to have nurses. The nurses were left with the choice of continuing to get less pay than their worth and really bad working hours or boycott and strike. They boycotted and came close to a strike but settled at the last second. Point is, it is completely acceptible to boycott something if people feel it is worthty to boycott and does not need to be some earth shattering condition to do so.
And I didn't create the parallel with your stance and rosa Parks. Someone simply applied a very specific stance you took and compared it wih another situation with the exact parameters. The question now seems to be, at what point to do you, personall, allow people to boycott something, assuming you have the power and authority to do such a thing? In my opinion, the very nature of boycotting goes against authority and thus no one person can have a say in whether on not a boycott is valid. If a boycott doesn't have merit they generally fall apart on their own accord. But if it does have merit, change is a natural result and it's usually those that suffered a perceived loss from the change that usually speak out the most that a boycott was bad.