My thoughts too; financially and professionally, these folks have done quite well for themselves, thank you, and will likely do even better once this company comes into its own through their stewardship. Perhaps they, especially the older ones, see no point in buying more shares when they are about to be handsomely rewarded soon by what they already have anyway.
Sadly, some people actually believe there’s no point in striving to accrue infinitely more wealth than one will ever possibly spend anyway, and appreciate the little things in life (poor misguided sods).