For some reason, almost all audio apps have very odd scroll and zooming behaviour (and home/end keys also do weird things). Also doing basic things like starting playback or recording from start or from cursor tends to be quite complex in many of them. It would be interesting to know why that is so. Maybe it is so that you don't accidentally trigger it? If you're just doing editing and never recording, you never want to trigger recording with r, only with some complex modifier combo. But if you're a musician, that's about all you do, hit record and stop and playback and stop.