I don’t get what piano roll exactly is, (I can’t load those images).
I think there is opposition between live&classic music makers and digital&progressive music makers.
Piano is old. It is true. 12 halftones in octave is also outdated approach.
Tracker’s grid system has its limitation that is true.
But piano has it also. It is true as well.
Keyboard of the PC is ugly. It is true.
You can’t press any combinations of keys you want and make PC recognize them.
Maximum from 3 to 5 keys simultaneously.
Why are you so bound to piano representation of sounds?
Try to use 144 notes in octave instead of poor 12 notes.
May be my thoughts have something in common with piano roll topic:
For those who haven’t read yet:
I do! Not only in HEX but in 64EX.
Notes, Instruments, Effects and parameters.
You know why? Because it is simpler and faster.
Actually it may be hex for computer.
When you are going through hell - just continue going. 
(enlightenment)
It is probably because pianist don’t know anything except piano with its 12 notes per octave.