Coming from a country where almost 80% of the personal transport are motorcycles
I agree with Rory's answer,
When you are driving fast , you will spend a lot less time in Neutral and when you stop you dont want to end up without power at the wheels so it makes sense to have the lowermost plonk a Gear.
After driving a 1N2345 bike setup for like 5 years , one day I had to drive a N1234 bike, most of the time I stopped the bike I was in neutral twisting the throttle only to make noise, riding becomes difficult and frustrating.
Thus the idea of a N1234 looks idiotic but the reason as to why most commuter segment bikes still have them is because of comfort while waiting for signal or being stationary, if you have to live with stop and go traffic everyday then having Neutral all the way down will actually be helpful as it will easily allow you to reach it no matter what(its sort of a gear in a N1234 setup) so there is no chance of you missing it.
Imagine stopping ever 15 yards and having to pull the clutch and search for the half neutral on a 1N2345 setup , by the time you figure it out the traffic starts to move and you are back where you started.I personally prefer holding onto the clutch instead of searching for the neutral as its a pain.