The primary factor influencing enhanced blurriness is the total angle you’re capturing (how many degrees you’ve turned around the object you’re capturing) as well as how far away the blurry object is from the axis you’re rotating around.
If you’d like to reduce the object’s degree of blurriness, move it closer to the center of rotation or change the scene/perspective in such a way to reduce total angle you’re capturing. You can read about how to do this in detail here.
Also, you can place the object being captured into a monotone background and then the blurriness of the background will go totally unnoticed.
Remember that all objects that you’d like to make sharp must not be moved or move around during capturing. This also refers to blinking or a person’s hair being blown by the wind.