its not magic. its an artisitc renditin of the feeling of impact.
You can easily create an impactful hit with sound, animation and blood (and maybe at times a very minor effect), without making it look like a magical spell. Source: I'm a game designer.
Floaty melee animations can really take away from the overall feel of combat. I good example of how not to do it is Dragon Age: Origins, which while a fantastic game, had surprisingly unsatisfying melee impacts. Personally, I want hits to be a bit forceful, but adding generic over the top particle effects to every melee skill does little in terms of achieving that. Instead, it tends to blur everything together, satiate the player's overall effect-tolerance, and hurt the wonder of actual magic in the game.
I urge Larian not to underestimate the impact this can have on the longtime enjoyment of combat for a lot of us. Let magic be magic.