It's not flimsy rhetoric at all but this would get deleted if I went into details.
There is a very big difference in this vaccine and say the polio vaccine that has decades of research behind it. If we had long term studies on it's safety then I wouldn't see a problem with it and I don't think many other people would either. It's not a crazy decision for an extremely fit 20 something year old to not want to stick in a needle in their arm to protect themselves from something they don't feel like they need to be protected from.
I don't think NFL players should be forced into a decision and that's exactly what the NFL is trying to do.
The polio vaccine was only in trial for a year, and that trial included millions of
children. The COVID-19 vaccines are an absolute cakewalk by comparison with respect to what has been put at hazard, both in trial and in mass distribution.
Further still, the mRNA research that forms the basis of both the Pfizer-BioNTech and Moderna COVID-19 vaccines actually
is decades old. It's become commonplace to characterize these vaccines as "experimental," which carries the negative connotation that not enough time has been spent developing them. The virus may be novel, but the vaccine technology simply is not.
As for that hypothetical 20-year-old, he may not feel the need to protect himself, but that's
never been the point of vaccination. Historically speaking, vaccines have been far less about protecting individuals and far more about protecting societies. Individual motivation matters less than the need to protect the group. The NFL isn't just concerned about those 20-year-olds, after all; it's also concerned about its coaches and referees, who skew much older than said 20-something's, and are thus more vulnerable to the effects of COVID-19.