I think you underrate the rainbow jersey. The bulk of the riders climbing off were doing so because they knew they didn't have the legs or their chance had gone which is common with circuit races. Those conditions would have tested most people. Looking at some of the photos and the amount of water on the road I think they would have been close to postponing it but changing the route was the best they could do. It's hard to postpone such an event.I believe many of those walking away from today's race was a form of protest. Just by having to chance the course it PROVES that it wasn't safe to race. Yes rider's health was at risk. With the conditions today, it's HIGHLY likely many of the riders will end up sick because of it. Many pulled out of that concern. With what Alaphilippe said at the end of the race, I'll be surprised if he doesn't end up sick and possibly ensure he can't race the fall classics for that reason. Yes the weather conditions did put the health of these riders at risk and the risk of illness is putting the end of the season for many of these riders at risk.