I can recall a recent flight from HNL back to the mainland where I boarded to find the overhead bin over my Polaris window pod completely full with the carry-ons from the passengers across the aisle from me (in the center seats). I don't know which category of pre-board they were in (somewhat elderly parents with middle-aged daughter) but they felt entitled to use my bins as more convenient than their own. Were the F bins completely full? No, I didn't have to go all the way back to E+ to put my things in an overhead but there are times when the F bins fill rapidly and -- in my limited experience -- pre-board passengers seem to feel more entitled to load up the bins than lower status passengers.