I'll just ask you one question - if you were out on your pushbike, cycling along and were perhaps momentarily distracted by ecstatic thoughts of all we have to look forward to once GWR▸ have finished "Building a Greater West", and in your euphoria failed to see someone using a pedestrian crossing, mowed them down causing serious injuries, how would you finance the consequent claim for compensation?
Similarly, if you were the victim and the perpetrator was uninsured and unable to compensate you, how would you feel?
If someone was being seriously injured by cyclists and cast aside uncompensated every hour of every single day you would have a very strong argument for compulsory insurance. But that doesn't happen. Reality is plenty of minor injuries and very occasionally a cyclist-caused tragedy.
Contrast that with motor vehicles and you are looking at dozens of life changing injuries and 7 deaths caused
every single day.
The scale of the damage caused by motor vehicles is completely and utterly out of proportion to the damage caused by cyclists.
We could have a society where everyone is insured for absolutely every risk (and whilst I wouldn't be in favour of that, I can certainly see that there are good arguments in support of going in that direction), but until we do it is not illogical to demand insurance against the major risks and not the minor ones.