It's marketing hype. In a 4-class aircraft, nobody wants to be in 4th Class, so BA calls it World Traveler.

Carriers align the level of service to the hard and soft product which the market demands. Hence, no wide seats for the premium cabin of intra-Europe flights, hence no freebie meal service for US domestic Economy.

Similarly, the JFK-LAX/SFO tends to support a more premium service than other TCON flights. Why? Because people will pay for it. The moment they won't, the lie flat F seats and extra appetizer are gone.