I agree with the OP, put dividers in the bin (if it is for 2 people put one divider, two for 3 people and so on), this is your cubby, do with it as you wish. If it doesnt fit in your cubby or under the seat in front of you (which does NOT include sticking out the front of the seat in front of you btw) then it gets checked.

The airlines also have to stop taking more and more bin space and marking it "for airline equipment use only", started with one bin up front and has creeped, saw 6 bins marked this last week. This already put 12 people out of bin space!

People are using this new study of 10,000 lost a day as justification to stop checking, that is less than 1% lost!!!!!!!!!! Deal with it if you are the 1% but stop punishing everyone to avoid something the chance of happening is less than winning the lottery.