Personally I would be fine with no mouselook if it wasn't for the overhaul in melee mechanics (timed blocking especially) - which I'm very happy for the change, and with the mod for mouselook/mouse-binding sword play is finally skill-based.
However, without the mod, with KB+M my fingers on WSAD/Shift/Space can not respond to Q (my block binding) fast enough compared to my RMB which is held down constantly in action cam. In all other swordplay games, PoP, Skyrim, MnB -> block is on the mouse. TW3 had LMB - fast attack, RMB - strong attack, however thanks to mouse button rebinding I had LMB - fast attack, MMB - strong attack, RMB - block. Index finger remains for attack.
This is why I am hoping for mouse button rebinding / mouse look toggle. Others have their own reasons why they wish it, especially for mouse button rebinding. For instance, since we no longer have click-to-move in action cam, nor the LMB+RMB = move forward functionality, others, including myself want to bind our MMB to move forward, which will allow for movement without the keyboard.
It's all about options.