Negative and positive rights are not bad and good rights. A negative right is a right that does not require anything from anybody. For example: the right to life or the right not to be killed. A positive right is a right that does require something from somebody else. For example: the right to have a car. Nobody has to do anything for someone to have the right to life, but somebody must do something for another person in order to get the car.
Classical liberals, such as John Locke, referred to natural rights–negative rights. Negative/natural rights are there from birth and everybody possesses them and can exercise them whenever they wish (even if this is at the same time as somebody else, because they do not interfere with another’s rights). However, positive rights cannot be exercised at the same time because they require coercion: somebody must force the other to do something.
Therefore, classical liberals conclude that positive rights aren’t real rights, because they weren’t there from the beginning and they cannot be exercised without anybody else’s interference.