Enjoyment of delicious, homegrown tomatoes is one reason to grow a kitchen garden. Some people who have room to grow only one item in a pot choose to devote their space to a tomato.
In the Deep South, where I live, people love their "'mater sandwiches." The simplest way to make one is to smear white bread with mayonnaise, add a giant, sick slab of fresh, homegrown tomato from a giant tomato, and sprinkle with salt and pepper to taste. Of course, there are variations. Some people toast the bread and add bacon and lettuce to make a BLT (bacon, lettuce, and tomato) sandwich. I personally enjoy adding fresh basil and a slice of fresh mozzarella cheese to my tomato sandwich, with a touch of balsamic vinegar. In the Deep South, we also enjoy slicing a tangy, firm, green tomato into thick slabs, breading it with some salted cornmeal, and lightly frying it, to make fried green tomatoes. Fried green tomatoes are usually served with a topping similar to hollandaise sauce.
When I was a child, my mother grew cherry tomatoes, in addition to the larger ones. To me, these tasted sweeter as well as tangier. I could never get enough of them. As an adult, I compensate by growing extra. As many get eaten in the garden as make it into the kitchen.
While common varieties that ship well (and hence can be sold at markets) are adequate, connoisseurs rave over this or that heirloom variety. While some heirloom varieties are also available in farmers markets, they are also expensive. People who grow their own tomatoes don't just save on cost. They also get to savor the superior texture and taste that can be achieved from a home garden.