I sometimes accidentally rotate Google Maps on my phone when zooming, and it annoys the hell out of me. I'm sure there might be a use case for orienting the map so north isn't up (for example, if you want to look at a route to a place with the place at the top of the map), but I haven't needed it yet. It's much more likely that if I'm using two fingers to gesture on a map, it's because I want to just zoom in and out, not rotate it.
As for Google Maps on mobile, some people like to have the map oriented so that "up" is the direction they are facing (i.e. their current direction of travel.) Annoys the hell out of me, too.
On Google Maps, try the single-finger double-tap-and-scroll for zoom without panning and rotation. Kinda nifty.
I sometimes accidentally rotate Google Maps on my phone when zooming, and it annoys the hell out of me. I'm sure there might be a use case for orienting the map so north isn't up (for example, if you want to look at a route to a place with the place at the top of the map), but I haven't needed it yet. It's much more likely that if I'm using two fingers to gesture on a map, it's because I want to just zoom in and out, not rotate it.