Well, I use a wacom tablet (since 15 years now) but it's not a Cintiq, my hands are on the tablets but my eyes on the screen. So if I rotate tablet but the picture doesn't rotate on screen, that's weird. Tablets with screen included are too expansive for most of us. And, anyway, many of us prefer to look the screen and not the tablet, so that our hands do not bother us to see the picture. This is why the canvas as to rotate on screen, for many of us.
That said, you are right. This rotating canvas is quite recent on most of softwares. Photoshop took a very long time before realizing it was very useful for us. And for me, fundamental, really.
Can't wait to see the final grid on Verve !