Thanks for the article links. Those pics firm up my thoughts regarding carry-on bags; unfortunately my thoughts are irrelevant to the people who make decisions. Nonetheless -- not only should size matter but also construction. Here's my first cut at changes to carry-on rules and how bags should be handled/treated during an evacuation.
1. Anything with wheels by definition is too big to carry on the aircraft, else why would it need wheels. Put it with checked bags.
2. One bag no bigger than a standard briefcase or small day pack. (By one bag I mean that if a woman decides to take her purse, that's her one bag.)
3. Carry-on bags brought to the emergency exit will be tossed out the door, no bag should go down the slide as it endangers all those behind. You can retrieve your bag once you're on the tarmac; if your precious laptop computer breaks, that's on you. (Passengers should be told during the safety brief that their bags are safer on the aircraft than they will be if tossed out the door.)
4. I reserve the right to add more restrictions to my list of things no one will implement.

I like the idea of locking down the overhead storage while seatbelt light is on and possibly while the aircraft is in flight.

But that's just my opinion.

Years ago I was on a flight from Guam to LA with a layover in Hawaii. I left the plane and airport, and walked to a nearby restaurant I liked for a nice dinner while the plane was fueled and prepared for the second leg. No carry-on bag to take with, no carry-on bag to leave behind and worry about while I was off the aircraft, just a boarding pass -- nice.