Same experience here - sometimes people get startled and angry if you pass unexpectedly on a path even when there's plenty of space. It's a catch-22, because sometimes calling "on your left" will cause a startled pedestrian to freeze in their tracks or even jump out to the left, so I find it's actually safest to stay quiet unless I really do need more room to pass safely.

Frustratingly, I've tried a bell thinking maybe it's a loud voice that makes people react unexpectedly, but people where I live aren't familiar enough with bike bells; most folks stop in their tracks and turn around to look with apparent curiosity for the source of the unusual noise!