Yes. Passengers are clearly untrustworthy. I almost never see the bins packed like that and usually people close when there is still room

The thing is that many “carryon” bags will not fit like that but it shouldnt matter. Even laying down there is usually room for three bags to match the number of seats.

Ive frequently see passengers close the bin when there are bags laying down the long way, wasting excess space whne there is clearly more room