Interesting thread.
Two persectives....
(1) context: if you're doing 420kts route up may be the way to go, but how many of us cruise much over 100kts?
(2) spacial awareness/orientation: some people can visualise time and space more easily than others.
Perhaps this is why there are two schools of thought about chart orientation and the choice is therefore a personal one rather than black and white.
Personally, I have used both approaches widely and on balance marginally prefer North up, simply because I can read the annotations more easily.
However, I find it very easy to make the mental flip between the line on the chart and what I see out of the front window. I visualise a little aeroplane flying down the track line per the moving map display on the TV screen on a BA airliner.