I think there's also a genetic component. I planted Roma seeds from a store bought tomato, grew the plant, and they still didn't have much flavour compared to any other garden tomato I've tried.
Yup. Store varieties are bread for exactly this: transportation. I read somewhere that unfortunately the taste and transportability are mutually exclusive when you go through traditional selective breeding.
Tomatoes are often hybrids, so growing from seed you'll be missing some of the characteristics of the parent. Not sure if this applies to roma tomatoes.
