it is not surprising that the design of auto arrangers is geared towards the home player, because that is where the biggest market lies. Your 'pro' market must be tiny in comparison.

I've been asked to make disks for music school purposes in my time, and see plenty of kids happy to start learning playing along to a sequence. Nowadays they just would not stand playing scales for hours, because there are too many other distractions in their world. If it gets more kids started, then surely there are greater chances that more will carry on and take their music further.

You could argue that auto arrangers have meant that never before have so many home players been able to produce such good sounds before.