I like to use the Tiny Tonitrus as a boss-killer to counter bolt weaknesses. Its damage is high enough to be only slightly less efficient than the Executioner's Gloves per-bullet. I find it works _very_ well on Ebrietas and Rom.
Well, if you want a justification, you could say that the spirits from the Executioner's Gloves are manifestations of magic, but Madaras Whistle summons an actual living creature, for which Bloodtinge would make more appropriate scaling. But why the game designers really chose that, I couldn't say.
You can't tell me Tiny Tonitrus isn't the coolest one. Sadge the big one doesn't measure up to its little brother at all. The thing breaks way to damn much.
The Hunter tools use "Bullets" as a resource, which is commonly dropped by enemies or found in the map. The tools themselves are infinite - as long as you have bullets, you can use the Hunter Tools.
I love the style of them all. They aren't spells, they're literally just tools that you pull out and use. It reminds me of The Witcher's signs where they're simple spells that are used as tools and nothing more.
People still widely replay it or start playing it, also, Bloodborne has a lot of things you can miss in your playthrough. It is also a good indicator for the achievements.