Dropping to zero has nothing to do with it, and in the example we're talking about would indeed drop to zero, and beyond.
It's not a question of 'arguing' it's a question of posting correct information - the fact that you have a different interpretation of a word to everyone else in the world doesn't mean you should try and convince everyone else to your incorrect point of view.
Switching is either ON or OFF - nothing else, nothing in between.
Your lightbulb example is fine, flicking the switch ON and OFF is 'switching' (the clue is in the name of the component
), varying the resistor (using a potentiometer) wouldn't be switching. That's the difference we're talking about in this thread.