I just flew DEN-SEA on Saturday. I watched an entire plane load of people load with some pretty questionable carry-ons. I even found myself wishing that Alaska had a sizer and enforced their carry-on rules. I saw huge, over-stuffed bags forced down the aisle with owners wearing equally large back packs bashing into people as they went down the aisle. Then, boarding came to a standstill as these same people tried to stuff these into the bins. I didn't just see this once, it was a common occurrence.
There was the usual gate announcement asking for volunteers to gate-check for free. Only a few took up the offer. Checked luggage was ready and waiting by the time passengers hit the washroom and took the train to baggage claim.
You have probably already figured out that trying to stuff the kitchen sink into the overhead bins is a pet peeve of mine.......