I am not sure if anyone covered this point while the debate was raging on cable routing...
but here goes anyway.....
Many years ago a bike mechanic told me the reason the continental bikes were 'laced' differently was because
they cycled on the other side of the road.
Here's the logic....
It was most important that a cyclist was able to make an off-side hand signal as this involves crossing traffic.
That is, a right hand signal in the UK, and a left hand signal on the Continent.
For stability etc the rear brake was judged to be the the best one to apply when only one hand was on the bars.
Therefore the rear brake lever was fitted to the 'kerbside' of the handlebars.
Alfredo Marcantonio
Twickenham, England.