When you have to dodge some boss' attack (that can one shot you) using a handful of iframes, twitch or no twitch, having a reliable framerate and a low input lag is crucial, and BB doesn't really perform that well in either.
Strategy can get you only so far in this game, especially in BB, where the builds available are essentially a variation of the agility build you had in Dark Souls.
If you can't dodge reliably, you can have all the strategies in the world planned, you're gonna die (unless you're massively over leveled and spam vials, i guess).
This is only amplified, if you take into consideration PvP, obviously.
Infact, i'd say responsiveness is even more important here than in, say, Dragon's Dogma.
That game has fucking horrid performance (much worse than BB, actually) and generally faster combat, but it's nowhere near as punishing, and it doesn't rely on exploiting iframes as much.
Try dodging in Dark Souls 2 at 60fps (on PC, but i assume it's the same on PS4) and then in BB, especially in areas where frame pacing is bad, and the general input lag + stuttering caused by the frame pacing issues, makes the difference pretty damn obvious.
Yes, you can work around it, yes you can still play and enjoy the game (and platinum it, like most here have done) but it doesn't change the fact that it is a pretty crucial aspect that they should be much more careful with.
You can adapt around a lot of problems in games, but they're still problems that should be fixed, or taken more into consideration.
Doesn't mean you can't like or even love these games (since a lot of people feel the need to point out how much they loved the game).