No it's not a good point.
For the vaccine... it's just terrible risk analysis that is equating two small probabilities. This is a common human error, but frankly not that hard to understand and overcome.
The risk of the vaccines are <<< the risk of COVID infection for all age groups. The presence of a risk does not make it prudent to avoid something if the act of avoiding exposes you to far greater risk.
The masking decision falls on more equal probabilities. The cost of wearing a mask during a race (annoying), the risk of COVID transmission outdoors (very slow), and the benefit a mask during a race (unknown).