Uh, so you watched stage 8 of the Tour as the only race and then just extrapolated to get to the conclusion that fans are impossible to keep away?
I think everybody knows what you say, and many organisers close off key parts of the routes (see Flanders for example), so I think people are being sufficiently "smart".
Drag..I like it...and I hate it..20 years of my life dedicated to working around it..
I watched the bulk of the Tour and much of the Giro and Vuelta.. Many stages had a fair amount of fans..It surprised me..Even more so was the ITV commentators saying that fans were banned from certain areas/zones/sections...Only to see a ton of them when the cameras arrived..Go back and read the chatter from that time/the commentary. There was dismay over fans being out.
Now track the second wave that hit Europe (France, Italy, Spain, the UK and the immediate environs of central Europe). It began in very early October. It is unfair to suggest that the tours caused it, but may have contributed to it. In other parts of the world, the second wave was not until early December, a full two months later.
To have 10,000-200,000 fans lining up to watch a race, on 21 out of 23 days in the four corners of any one nation..or simply for a one day race, will inevitably lead to problems..Nations that have locked down the hardest have generally seen the least deaths (Scandinavia aside).
Stay home, stay safe..let the bike race be handled exclusively by the riders/staff and organizers and watch on TV. And all would have been okay...but no one listens and so things get canceled.