Why? Other than being an ugly fish, this is no different than stuffed crab, stuffed clams, oysters Rockefeller, lemon stuffed grilled branzino, etc.
These poor fish are just ugly as hell and the dish itself taken out of context and labeled “Tacos.” I’d never thought about it before your comment but it seems to me that including the whole animal on the plate is the least wasteful and most respectful way to eat it. When you can see its face, there’s no hiding that what you’re eating was once sentient. How much is wasted is left for the person holding the fork to decide.