I think my tongue is tuned to good food = tasting good! My 'tongue' doesn't like too much salt or fat, and I'm repulsed by foods marketed to taste good because I'm not that demographic at all. Healthy food tastes good to me. It's about training your palate I suppose, if you weren't raised that way to start with. There's also texture, memory, sight - a whole heap of things that vary due to culture or from family to family, upbringing to upbringing, person to person.

Some people don't taste as much because they can't smell - aroma is pretty important too. Eating is such a complex thing!