Here's the thing though... nobody wants to see riders injured, but if a rider takes a risk divebombing a colleague, following somebody too close on a descent, or launching into a blind corner at full speed... they know that the risk is there and what the consequences are if they come off. If they crash because they rode like a reckless lunatic, then I'm not going to hold the organiser responsible. If they crash because the organiser put a hairpin bend on dusty roads 600m from the end of a sprint stage and the riders simply couldn't negotiate it safely, then I'm not going to hold the péloton responsible.
But if they crash because a rider rode like a reckless lunatic, but the impact of the crash is worsened by the organisers' doing, such as the bricks in the Tour de Pologne or the uncovered culvert in the Itzulia... it doesn't miraculously absolve the riders of blame for the incident and lay it all on the organisers' door, because the crash was the riders' fault.
Responsibility, from legal point of view, that is something, AFAIK, currently non existent in the sense of clarity. AFAIK you as a rider, or representative, basically signs a piece of paper, for being able to participate at some stage/race, for the organiser not to be responsible in case you injure yourself. And in the end it's not like organiser will have any initiative to care if it's your fault or not. This is something fans are usually caught up with determining, mostly for entertainment purposes. So currently more or less a wild west.
Why?
What you can do, as a riders that got injured, is you can still take legal action in a regular court but i rarely see it happen. For example i read a while back a rider is taking legal action against an organizer and there was or still is an ongoing dispute between riders from that prominent Tour de Pologne crash.
Now on why it took 100 years of road cycling and for legal responsibility to still be so inadequate. It's rather clear i guess, nobody else wants to take any responsibility whatsoever, it's all on riders ATM.
You say the modern pro péloton can't change overnight, but it can change an awful lot faster - and is a lot more realistic - than changing the entire infrastructure of Europe and everywhere else that hosts bike races to make it so that the riders can plunge into any corner they like at any speed they like without there being an inherent risk in doing so.
We discussed this in detail and i feel that the initial idea, on how you need to secure 200km of roads per stage, that turned out to be not as bad. That is it usually comes down to a couple of kilometres per stage. Bridges, corners on dangerous descends, finale ... So all in all no biggie. In terms of setting some inflatable barriers with commercial space available on them and making sure that road sections don't have big holes in the surface. It's like if we at first thought 200km seems a whole lot, it does, but realistically you need to make sure you secured in between 1% to 5% of the exposed sections. For the rest, less exposed sections, you carry a personal airbag anyway. Yeah, i know, not yet. I am talking from the perspective on where a decision will be made to actually do something. Beyond measuring socks and things like that.
You are using F1 as the comparative, but you need to use something like rally, the Pikes Peak hill climb or the Isle of Man TT, because cycling doesn't use purpose-built courses, and it has to deal with roads that come with all of the trappings that regular public use entails. They will never be able to make the sport truly 'safe', only 'safer'. There is an upper limit to what the UCI and the race organisers can do, the péloton is not absolved of responsibility for safety just because they want to go 100% all the time and not have to think about the risk. Most of the riders who enter the Isle of Man TT want to go 100% all the time too. For 269 of them, it's been the last thing they've ever wanted to do.
I used F1 as an example to say FIA, as a governing body, takes riders safety seriously and objectively the number of injuries and deaths decreased dramatically. That is on the same purpose-built course type of race. On where UCI, as a governing body, doesn't take riders safety seriously and objectively the number of injuries and even deaths is high. UCI can do better and we will force them to do better. I am sure that the number of injuries will reduce in the next decade and that UCI will play an important role in achieving that, if they want it or not, better if they take a positive stance on it then to be forced into it. Either way it will happen. For example three to five years back you couldn't unite the riders, now that isn't a problem any more, organisers are as such under more pressure, UCI is next. It's like with doping, UCI was the last stronghold. Safety is now what doping was back then, we are in pre-safe era and that is about to change.