'Those who eat Chilean salmon can't imagine how much human blood it carries'
theguardian.com
theguardian.com
How do you judge it as "clickbait"?
As for the “why”: as an in-context quote it’s fine; out of context - as an article heading - there’s a high chance that the reader will understand it literally and be shocked by it. As pointed out in the other comments. A heading that is misleadingly designed to shock is the definition of clickbait. If, as I said, it was intentional.
The ones sent to go swimming with the fishes
It's actually definition #2 on google "Blood: 2. violence involving bloodshed."
I'm curious how the metaphor is so far from one's mind when reading.