Different folks have different preferences.
I agree that on a footpath pedestrians should be treated as having priority.
A semi-common way I use my bell: when on a shared footpath with plenty of space to take over, I often use my bell when I'm still ten meters away, so that I don't give pedestrians are heart attack by suddenly dashing right past them.
(I have a nice ding dong bell. They don't seem to mind. It also helps that I often have a cheerful five year old in the back.)