"Is dangerous cycling a problem" BBC

Aside from the lack of brake lights, slowing through the box puts additional strain on the gear train (I seem to recall the Advanced Motorists cite this as a reason not to do it) and it causes unnecessary wear on the clutch plates - brake pads and disc/ drums are relatively speaking very cheap and easy to replace.

Agreed that it still has nothing to do with shit driving.

This is true if you rely on the syncromesh to do it, not so if you use the throttle to match the speeds in the gear train as you go down.

If you get it right you don't need to use the clutch at all- into neutral, blip the throttle, into gear.

I don't do this with my car, but hire cars are fair game.