We want to show sharks as animals that are completely harmless and gentle, but this is simply not the case. While sharks are not inherently violent, interacting with them without proper training or education is dangerous. Sharks are predators and some of them just aren’t in the “gentle” category.
We don’t need to call sharks “dangerous” to avoid bad interactions, but we should be respecting their power and their role as a predator. I personally don’t see the issue with talking about sharks in a positive way, just as long as you realize people need to be educated on their not-so-cute side too.
IMO, the only sharks that should be referred to as harmless are filter-feeders, tiny ones like cat sharks, or small deepsea ones that no human will encounter alive. Sharks that don’t attack humans but will bite if provoked are better described as “mostly” or “generally” harmless, since they’re entirely capable of harm. Larger ones I’d just call “unaggressive” or something of the sort. Things like hammerheads are not harmless. They’re unlikely to attack you, but they’re capable of massive harm if provoked or during a test-attack.
I’m not sure I’d use “gentle” to describe any other than filter-feeders, and maybe not even them. To me, “gentle” implies deliberate gentleness. Whale sharks won’t hurt you, but not because they’re trying not to hurt you, because they don’t have a reason or a good method to hurt you.