On recent full flights, I noticed that passengers after me tended to load overhead compartments in a suboptimal fashion that failed to maximize the amount of baggage that could fit in each one.
The usual situation is that a passenger with a rollaboard would not even try to put it in wheels-out or handle-out (so that the long dimension is perpendicular to the aisle). Instead, they just put the rollaboards in parallel to the aisle, wasting overhead space. Flight attendants did not even try to turn the rollaboards that direction when looking for more space for later arriving passengers.
Any reason why people (including flight attendants) seem to be unaware of optimal overhead compartment packing?
They don't fly much, and/or the FA's see it as "not my job" except in extreme situations.
I always try to get mine in wheels-out or handle-out, and test the bin lid to make sure it will close, before I sit down (the exception being on the 2-seat side of an MD-80/DC-9, where they're supposed to go lengthwise). Last night I had an unexpected and pleasant experience with an AA FA "protecting" the bin nearest the bulkhead in Y, where I was sitting, by keeping it closed until the bulkhead passengers showed up, to ensure we'd have space.
Haven't seen much of that lately.