I find this whole thing to be a breath of fresh air. The way I see it...

AC: There are rules and we are going to enforce them
Pax: OK as long as its uniformly enforced.
DYKWIA: OK but what about my [insert issue here?]. I need to carry my entire life on board with me because my time and convenience are more valuable than any other issue you can mention.
AC: There are rules and we are going to enforce them.

As someone who is a "laptop bag only in the cabin" person - with all my other stuff checked, it is a source of constant amusement and annoyance when I get on the plane and there is nowhere for me to put my single bag except for under the seat. Meanwhile, Mr DYKWIA has three articles in the bin and nothing under the seat because "he needs the legroom".

Last week, YUL-YVR in J on a 320. Tight connection into YUL so I was not the first to get in the J cabin and already all the bins were full. Nowhere to put my MEC bike courier bag (v. handy for short duration trips). I asked who owned all these bags and the DYKWIA in front of me moved one of his three sizeable carry-ons around and looked at me as if to question who I though I was - encroaching on his manifest destiny to occupy limitless bin space.

Well I too have legs and my legs welcome the enforcement. It's LONG overdue.

Let the flaming commence.