Regarding your stow under the seat comment... I'm a tall dude. I'm cramped enough as is so I'm not putting crap under the seat in front of me as it's the only place I can stretch out. I also check my suitcase virtually everytime.
I do however bring on a carry-on relatively small backpack with my laptop. I put it in the overhead bin... not under the seat. I don't feel guilty at all. All the other people bringing the biggest ass suitcase possible, along with a backpack and maybe a purse too... they're the ones hogging space, not me with my one backpack in overhead. Seats are crammed enough. You wanna be angry, be mad at the airlines making seats so small and being bag charge crazy.