A lot of interesting food for thought in this article, but I find the focus on parasites as particularly fucked up or evil puzzling. It seems like an aesthetic distinction, not a categorical one. There are plenty of vertebrate predators that will bring their young still-living prey to "play with" and devour. This seems hardly better, especially since the prey in this case is often much more capable of experiencing fear and suffering than a caterpillar or a snail.

It's also interesting to consider that fear itself is probably an adaptation that helps the propagation of DNA. The fact that animals and humans can experience fear at all tells us that we're not in a kind universe.