This is what some author thinks. This is obviously wrong.
Women are underrepresented in physics but we do not know the causes. It would be nice if there were more women but the claim below is false:
Fact: Everything is relative; it depends on your frame of reference.
This means exactly the opposite of what the author above thinks and many also think in popular science books. In general relativity it means that things may be occurring in one frame observed by observer A that another observer B does not observe in another frame. But the theory gives the tools to observer B to infer what observer A is experiencing, and vice versa.
The theory does not claim A and B should experience the same states. In fact, events can be in the future of observer A but in the past of observer B.
Fact: Different observers experience different things if they are in different reference frames (i.e., they are moving relative to each other).
Some observer can be moving at 0.6 times the speed of light and accelerating and some other at 0.9 times the speed of light and decelerating, for example.
Therefore, the other conclusion of the author mentioned could have been be that different people are usually in different reality states depending on their relative motion rather than general relativity not working.