Why does the Spanish Inquisition have so much publicity?

Because it is a perfect example of what happens when you replace logic and reason with religion. It is no different than the Salem Witch Trials, very few people died, less than 2 dozen, but it is used as a perfect example of m hysteria caused by religion, which is why it is well-known. The death tolls themselves aren't high, but the way their societies thought and supported these crazy things are what make it popular (I think)