Uh, if normality is a statistical number it is objective for each population. The measures are done the same way, it's literally math. Obviously normality will vary across populations, but the that just makes the concept now effective. A collectivist country is going to use the same equations as individualistic country and their normals will fit population. However, humans are humans as well.
When you reject normality, essentially when you reject the existence of statistical means, you demand a level playing field when one can't exist. You only build stairs and expect those in wheelchairs to walk up them. When you have abnormality you accept that all people have different benefits, flaws, needs, etc.