We agree to disagree, then. Locking to Kos was for me a recipe for disaster and as soon as he started jumping around near me (in second form) the camera went berserk. I'd admit that the camera is much worse in other fights and has always been a low point for the entire series, but still... Also, while I'll agree most of its attacks won't kill you in one hit, more often than not they will be part of a chain that will stunlock you to dead from a full life bar, so its the same thing. I've watched a lot of streamers fighting him by now, and believe me, this is very, very common.
I agree, however that the key in this boss is to react very quickly. That is the reason this boss, just like Ludwig, is a big skill roadblock that is designed simply to prevent some kind of players from accessing the content. Why? And how is this good design in any way? The rest of Bloodborne, and I'd say the rest of the Souls series, is nothing like this. This case reminds me of Lud & Zallen in DS2, which at least was optional, intended to be played in coop, and you could still brute force through them, even solo, with proper gear.
The Bloodborne DLC is a huge step down in my opinion and has changed my mind entirely about DS3. Now I will wait cautiously for reviews before buying.