Because those people haven't internalized the idea of an analogy. An analogy is necessarily an imperfect abstraction, and some people think finding out those imperfections means you somehow found a flaw somewhere. Their brain (not singling out our friend here, just people in general) goes towards the exceptions in a model, because its far easier to find superficial flaws than it is to realize deeper meaning.

This is a wonderful observation. It is a lesson that I took far too long to learn as a young and somewhat insecure programmer, thereby becoming entangled in many unproductive arguments.

Perhaps not this case, but analogies when used as persuasion devices, can get quite dangerous. It's important to realize when they are false, or misleading, or overly reductionist, in order not to fall for them.

I certainly fell for a few false ones in the past. Sometimes only deeper meaning is that someone's trying to manipulate you.

I also was just thinking about those poor woman who got killed in a Chinese escalator accident a few years ago, totally missing the analogy's point.

But that's just a problem with analogies, they trigger different ideas in different people's heads.

Just wanted to thank you for adding the term "bikeshedder" to my vocabulary.

Being pedantic can have it's merits but yes, it can get old.