I don't know what to tell you Mrs. H. :? Maybe it has to do with location and climate.
I can actually spit a 'mater seed on the ground here, and grow a vine that yields fruit.
All I do is put a plant in the ground, keep the weeds back, and have tomatoes to give away.
Now, every other year, I cover the garden spot with barn drippin's that have weathered a bit,
and turn it under in the fall. Maybe that has something to do with it.

Other than that,
I don't use any chemicals or other fertilizer on my garden, and just pick off any bugs and worms that I see.
But you're right the taste of store bought tomatoes don't hold a candle to one ripe out of the garden.