We are facing switches here, not pushbuttons. In pushbuttons it's one transition triggers an event. Say, button goes low, a counter gets increased. Button goes up, counter doesn't change but the system gets ready to intercept another push. In this case it's level that triggers a state, both transitions trigger state change - on/off.
Yes, it's "unhealthy" to send 15 "on/off" events when one is needed, but that can be easily solved with increasing polling delays, say, the state is read every 0.1s and not every 0.1ms. This way all the bounce will be "settled" inbetween the readouts and the delay is still unnoticable. If single "bounce" still happens though, it's pretty much harmless, a blink of lights etc. No problem of 2 letters appearing where one should or counter getting increased by 3 instead of by 1. State toggle switch needs much less effort than event trigger pushbuttons.