How the volume control behaves is rather fundamental behavior, and everyone that uses MC "expects" the current behavior to some degree, so even if you think its not ideal right now, its unlikely to just change overnight, as that would be rather disruptive.
The slider does work "predictably" afterall, just at 0.5dB steps over most of its width instead of your suggested 0.33dB steps - not really a huge significant difference. It only falls of steeper at low levels, because people asked for that at some point, since they needed much lower levels then a pure log scale of 0.5 per percent could give them (and 0.33 per percent would even be worse in that regard, since at 0 its just -33dB)
So in short, different people have different requirements. Some have strong headphone dacs and need to listen at -50dB, some have their system tuned in such a way that they need to live between 0dB and -10dB, but short of making the ranges entirely customizable we're not going to make everyone happy (and this would be a rather big change since its tied into MCs operation at various points).