I agree with you. But I'd like to point out that the color specifications and audio response ranges we have are pretty much an exact science despite being informed by human experiment. Human experiment is not at all exclusionary to a topic of study being an exact science; it just makes the truth harder to discern. We are still coming up with new color spaces that claim to match the human range better, after decades of research.

Regarding typography however, I argue that there are a multitude of concerns such as readability, aesthetic, and sustainence of focus. People will have different preferences and rankings for which concerns should be most optimized. Thus, the science of typography may need to be parameterized by the context of the text and what it is going to be used for.