I see where you are coming from 86 but notation has limits. It simply cant reflect some of the things that go on in live music accurately. I learnt the classical route and used to think that notation and playing in such a way to accurately reflect the written notes was in some way a holy grail. I now realise that modern western notation is in fact a hotch potch of compromises that is incapable of reflecting accurately AND simply, some of the necessary things we do when we play in a certain style.
For example, I once tried to notate a sax solo where the player started each note a little early for effect, if I wrote this strictly then I ended up with a mess of hemidemisemiquavers for what was essentially a solo in simple eigths. Another example, when playing a acoustic guitar solo the sustain of the notes is often as much a function of how the fingers move and how many open strings there are. If you tried to notate this exactly then you would have to note what maybe essentially easy phrases with various different rests intertwined.
Notation also fails to signify some essential things. Often a player will put a heavier accent on the first and third beats of 4/4 but this is not written. The velocity and attack of different notes is usually left to the performeer though some indications are occasionally given. Often a player will sustain a note whilst a second and even a third and fourth note are played (subconsciously). If all of these notes (ie. on a guitar) were written as played then again one would get a very cluttered score which would be unreadable and unecessaraliy pedantic. For these reasons I dont see that notation can reflect a live perfomance, especially something like a blues harmonic solo or a rock guitar riff with lots of feedback. Try playing some simple solo (with feel) into a sequencer a (which supports scoring) and take a look at the result - a labrynth of clutter and confusion.
As for refecting dynamics, in the real world a crescendo for example is not just a increase in the amplitude of a sound, but as the instrument(s) is stressed a totally different wave form casn be found, the attack can change, vibrato and much more

In the round I am saying that there is much more to this than meets the eye. Cubase has two concepts which help. They have 'display quantise' which distinguishes between two notations the 'real' notation of what is played, (which is often impossible to read) and the tweaked 'display' which is a simplification which does NOT strictly represent what you hear. It laos has expression maps which allow the selection of (e.g. different staccato samples, for the SAME notation symbol. This is important because even though the same symbol is used on the page a player will use a range of different staccato sounds for different contexts. In fact I vbelive that in a whole lifetime of playing the sax I have never actually made the same sound twice - in oscilloscope terms.

I agree weith you that the interfac e is outdated though.

Just IMO.... its complex!