Whenever I've flown Alaska they've certainly never "encouraged" people to bring carry-ons. Instead, they announce that it's a full flight, space is limited in the cabin, and they'll check your bag for free if you want. Which is exactly what most other airlines do when I've travelled in the last decade. Certainly haven't encountered Hawaiian having people standing at check-in telling people to check bags. I still prefer Hawaiian to Alaska for flights to the mainland. Doubt I'll switch to SW.