Perimides writings on block universe would later become Einsteins theory of the same name. Copernicus had only limited data, and inferential mathematical equations to verify his work. Kepler and Brahe had accurate instruments such as optics and clocks to physically record natural phenomena. Einstein could easily photograph the stars at night, and then compare them to photos of the same stars during solar eclipses to evidence a block universe. Its understandable that Popper would profess that a myth should not be discounted based on it's limited empirical data.
Demarcation is a necessary step in the investigation of scientific theories.
The line at which science meets pseudoscience is one that can be manipulated by the scientist to programmatically refine theories. Pushing a theory to this line, without crossing it, could lead to valuable new structures of a science. Inductive reasoning is a valuable part of cognition, but also a boundary that should be respected by the scientist. The boundaries of science can be induced into what once was the realm of myths, but it must be supported by emperical data. It is possible to overstep that boundary in error.