Thanks for clarifying. I meant valid, non-fallacious argument.
More often than not I see analogies (ab)used as a tool to construct a straw man. This particular case demonstrates how analogy takes discussion away from merits and downsides of C to an emotionally charged subject of cancerogenic substances, as other commenters highlighted in this thread.
Personally, I don't think it's the commenter's fault that some others have such strong emotions to the analogy that they're distracted from the point. There's no indication that the commenter was appealing to emotion and, as others have also pointed out, making a comparison to an "emotionally charged" subject does not nullify the validity of the comparison. In fact, it's fallacious to falsely invalidate the argument based on some cherry-picked, subjective, peripheral perspective like that. In my opinion, the appeal to emotion and the derailment of the discussion is from those doing so, not the original commenter.
It seemed like just a simple, general, easily-mappable analogy that most people would get, even non-programmer laymen, that emphasizes that unsafe should be replaced with safe. Any analogy of something unsafe can be seen as "emotionally charged" if someone was personally impacted by it.
More often than not I see analogies (ab)used as a tool to construct a straw man. This particular case demonstrates how analogy takes discussion away from merits and downsides of C to an emotionally charged subject of cancerogenic substances, as other commenters highlighted in this thread.
reply