Exactly, its quite simple but must apply for all modes of transport. Im fully aware that some cars will squeeze an amber or early red (which is still illegal) however it not as blatant as a deliberate act to jump the lights at any stage.
From the cyclist point of view jumping early may be because they don't trust the car behind them in the lane to have any patience and squeeze by (I get this everyday), but of course they might just be an arse thinking the light is nothing but an inconvenience to them. In some, some cases I'd understand it, but don't do it.
From the driving point of view, it seems to be ah sure I'll gamble, save a minute or so, my journey is terribly important. In no cases except medical emergency to I understand it