There's a time and place where even dinging a bell is unnecessarily, well, "insistent", if that's the right word.
What I'm thinking of are places like down by the reflecting pool between the Lincoln Memorial and Washington Monument, where everyone is guided onto the walkways between posts and chains (which I don't mind; otherwise, everyone would walk everywhere and trample the grass into dust). One time when I was down there at the Lincoln end near the Vietnam Memorial, a cycling couple was approaching the walkway intersection, ding-ding-dinging over and over, hoping that the families wandering around would step aside to let them through.
Now, I don't mind announcing one's presence, and understand that we don't want someone to accidentally step right in front of a moving cyclist -- but, honestly, was it necessary to flick their dingers so much? Were these riders in enough of a hurry on their Sunday cruise that they couldn't chill out, slow down, and pick their way through at a slow walking pace?
MUPs are one thing, open streets are another (I once called out to a lady wandering into the street, "Whoa, whoa, traffic, traffic!" so that she wouldn't get hit by the cars coming behind me), but c'mon, don't be That Cyclist. Unless you're an ambulance or a cop, there's no reason to force your way through a crowd. And if you're trying to maintain a certain speed for the sake of exercise, you really need to find a less-crowded area, or at least a better time of day.