In a previous job, I would often not get a chance to eat prior to heading the the airport, and I needed to hit the ground running once I arrived (so needed to sleep asap), so being able to get a meal at a lounge was great...which is why some airlines, depending on location, have this service. Not everyone has the time/schedule to partake in onboard service (and I'm actually surprised that some frequent flyers here don't understand that...).