I just don't feel the whole 8 direction whipping. It's a whip, not a sword. Just using a wip accurately straight ahead is hard enough. Accurate 8way whipping is just nonsense.
As much as I like the straight no bs whipping, there are many things about Castlevania that are nonsense. For one, why on Earth Dracula has an array of fantastical monsters from every different mythology localised entirely within his castle which can manifest at any given moment after crumbling.
Back to the whipping, anyone who has used a whip, lassoo etc in real life will know that the way the Belmonts (and Morrises) wield their Vampire Killer is not typical. One does not generally hit targets on pin point with a whip, in realtime you'd be more likely to take out a heap of lesser enemies with one attack. But this is what makes the Belmonts so damn special, they have this ability and this is partly why the chosen descendants of the Belmont lineage undergo such training.
End of the day, multidirectional whipping is to give the player more control of the protagonist, it was never about being realistic. Speaking of swords, it's not realistic for Soma to swing the Claimh Solais over his head consistently (in combo chains) without injuring his body. It's also not realistic to wake up in an eclipse, but here we are.