I think your point on bike etiquette is valid barakta, it isn't clear how pedestrians/cyclists should inform each other and communicate. I get about as many pedestrians telling me they didn't hear me as ones who shriek that I'm talking to them.
It's part of the strange
BRITISH attitude to bikes that ian mentions. The rules are clear enough - you're supposed to ring your bell to make people aware of your presence and slow down and proceed with caution. But any attempted warning is perceived as a GETOUTOFMYWAY! by a significant minority of pedestrians, so most of the time it's better not to bother. And hence the status quo is perpetuated.
I don't like to use "on your left/right" when passing non-cyclists, because they're unlikely to be familiar with the protocol, and even if they know the difference between left and right, some will hear a direction and move that way.
My pragmatic solution (beyond riding where pedestrians usually aren't) is to make a neutral mechanical noise (or if it's dark enough, shine enough light that they can see it illuminating their surroundings), and hope they notice you and work out what to do on their own.