You have successfully figured out that nobody used the word incomprehensible in the reddit thread :)

I was only attempting to mindread - sorry for poor use of quotes.

Perhaps interestingly, my model here is the reverse of my model for humans failing at hypotheticals: if you ask people to consider the hypothetical where punching kittens is a good idea for some low-probability reason, and ask them what they'd do about it, they can't do it properly. It's not in the design specs of their brain. Similarly, if someone encounters the same feeling of finding it hard to think about something, I suspect they conflate that with it being a hypothetical of low probability.