I agree, these gentlemen train incredibly hard all year (and have been doing so for much of their lives) only to get injured by some selfish and clueless fan and have to drop.
The behavior of fans during climbing segments is even more infuriating to me. At the bare minimum, it's incredibly disrespectful of the riders.

In the case of a significant fan interference like this, organizers stop the entire race and note the time gaps between groups. Once the injuries and mechanicals are tended to, they restart with those same time gaps.