Additionally it's probably a rule that was written in blood and it also isn't an obvious feature that someone would know about and base their purchase decision on.
I'm fairly certain just about every single half decent parent is completely obsessed with anything that might even possibly be a choking hazard. Kids are surprisingly strong and capable of completely chimping things to shreds. If there's choking zone beads on a toy, it's not getting bought, regardless of whether or not if they have 'ventilation holes' in them.
