Genetically we are all different, but experience also ties into it.

Humans have different concentrations of taste buds and tolerance for certain types of food.

Some people love spicy food and can eat things that's nuclear hot, while others hate it because it destroys their stomach.

Some people won't eat Cilantro because they have a mutation that makes it taste like soap.

Some people won't eat a certain type of food because it made them throw up once, or they were force fed a certain food by their parents and they refuse to eat it as adults.

Or they may have allergies. Severe allergies have a way of making foods very unappealing.