Kind of you to link the Wiki page as the full sentence that mentions Mullis' astrology belief is: "Mullis professed a belief in astrology and wrote about an encounter with a fluorescent, talking raccoon that he suggested might have been an extraterrestrial alien."

He's a great example of why being an expert in a specific thing does not make you an expert in all things.

Maybe it is just too early in the morning for me, but Kary Mullis disagrees with what in particular? That astrologers disagree with each other? That astrology does no better than random guessing?

The wiki link has a single line, saying that he believed in astrology, but that's it. I'm struggling to see what point you intended with your comment.

This is the kind of statement that the Appeal to Authority fallacy was made for. Just because someone is an expert in one field doesn't mean their opinions matter in every field.

All this points to is the danger of believing someone based on reputation rather than evidence.

Empirical evidence is the basis of science, not reputation. No one, no matter what they've done before, gets to present their hypotheses as fact without evidence.

One problem that outsiders to a field have is that we may lack the background knowledge to evaluate the evidence for a hypothesis. In that case, I try to rely on consensus rather than one expert opinion.

Many scientists hold religious beliefs, I don't see the difference here?

Fluorescent talking alien raccoons! Wow, some hallucinogen.