Agreed.  In the US, anyhow, only 6% of two vehicle motorcycle crashes were rear-enders in 2015.  When I ride in traffic, I usually gently tap the front brake 3 or 4 times any time I am slowing down to give drivers to the rear a heads up -- especially if I am downshifting rather than braking.  Same effect, less hassle......and 120 bucks cheaper.