As Boeing point out in the Flight Crew Training Manual, a smooth landing is not necessarily a safe landing. The plane should be flown onto the runway at the desired speed and touchdown point. Done correctly, then the resulting landing will most likely be firm but not necessarily a bone-cruncher. This will ensure that spoilers etc will deploy without hesitation and minimise chances of tail strikes.
I'm sure SWA pilots will just fly the plane like they are meant to, and being positive on the touchdown is the way it's meant to be done to achieve the "Boeing Landing"
But who am I kidding, everybody loves a greaser from time to time
