Spot on. Racing is illegal on public roads and sadly that is what SOME riders do. Trying to excuse it by saying there are nobs in all walks of life is like saying it's ok to mug someone bacause it happens all over the country.
Further the only reason speed limits don't apply to cycles is historic. VERY few cyclists could exceed the 30 limit over half a century ago when the limits were being brought in on a large scale. More to the point is that there are more and more 20 zones now, a speed not that difficult to exceed. Believe it or not cyclists have a bit of a charmed life at the mo, very few rules actually do apply to them and those that do are often broken because they can "get away with it" [riding on the footpath for one, no requirement for any form of insurance, even the most basic 3rd party, for another], even these actions often being defended or "excused" by people on this very forum.
Do as you will but the heavy hand of officialdom will [given any excuse] come down even harder on ALL road users and to believe otherwise is, at best optimistic, at worst -well---.