Agreed. The sample is very likely tainted by factors that made success much more likely than average if we believe that NFL coaches are both conservative (they forgo punts only when the odds are much in their favor) and rational (they are win maximizing).
Still, there is probably a case to be made that coaches should be a bit more aggressive, but that edge could be small enough that other factors (like perceived incompetence) dominate it.
Still, there is probably a case to be made that coaches should be a bit more aggressive, but that edge could be small enough that other factors (like perceived incompetence) dominate it.