Sometimes you need to prevent zoom in order to implement your own zoom though. For example if you're making a WebGL app, or if you're making a map zooming widg

Sometimes you need to prevent zoom in order to implement your own zoom though. For example if you're making a WebGL app, or if you're making a map zooming widget that needs to progressively load more local detail as the user zooms in on an area. If you don't disable zoom, the OS and your zoom logic will be fighting over the pinch gesture.