RAS, what you say is true, all (civilan) bikers have the same rights- as do all other motorists. However, as I often say to my "advanced" students- it is no good being in the right but DEAD!
It is a fact that riders using some form of conspicuity, be it hi-viz clothing, bike livery or running lights are LESS LIKELY to be involved in accidents. Nobody is accident proof. My last major accident was when I was riding an ST1100, headlights on and wearing a hi-viz harness. It was broad daylight and at low speed (about 15mph). The driver pulled out of a side turning on the offside, came across the road and hit the back of the bike. He had seen me, he just musjudged the rate of closure and mishandled the car- the reason? He was drunk.
If somebody chooses to ride all in black with no lights it is entirely up to them and they are simply accepting that they have a higher probability of having an accident. I choose to be conspicuous and maximise the chances of other motorists seeing me and accounting for my presence in their driving plan. The chances of having an accident are reduced if BOTH parties are accounting for eachother. If you don't give the other party the best chance to see you you are already eroding your safety margins before you start.
EVERYBODY makes mistakes. On the day that we make the mistake it may be the other party that has to avoid an accident. If they haven't seen you then how can they? Yes, you can argue about drivers on their phones or being otherwise distracted, but these are a minority and most drivers are watching the road and are likely to see you.
BP