There's a large subpopulation of people flying who seem to have no idea how planes and airports work. Maybe they're sleep deprived or it's their first time flying, but these announcements are targeted at them.
If I could walk from the plane to the luggage area and my luggage was already there 90% of the time, I probably would check more things.
However, the US airports simply don't employ enough people to move the luggage around fast enough.
The is 100% correctable by employing more people. But some CEO needs another yacht, so they don't. So, I simply don't check luggage.
I flew into the Orange County Airport before they tore it down and made it like the others. Felt very civilized. As I get older I find the hostile public spaces and infrastructure more and more annoying.