For the context of this topic (blind usage of OpenMPT) it doesn't really make a difference (except that left/right/up/down keys would be swapped)... but completely ignoring the topic, I don't really think it would be all that helpful. Just thinking about it practically, pattern cells are wider than they are tall, just like screens. If you now made patterns go to the right instead of the bottom, you would see a lot less context in time (only 20-30 rows instead of 60+), while at the same time seeing 60+ channels, which is more than what most people use. That's a pretty bad trade, I think, and it's not like the vertically scrolling instead of horizontally scrolling timeline is what makes trackers more complex to use than traditional DAWs.