Home-grown fruit most definitely can be sweeter, juicier and more flavorful than store-bought, especially in the case of stone fruits like peaches, nectarine, apricots, plums and the new interspecific hybrids. In a home planting these fruits can be allowed to ripen completely on the tree, fully developing their sugars and complex flavors. The stone fruits of commerce, on the other hand, must be picked while still firm, before those final days of ripening and softening, in order to withstand handling and shipping.
As many fruit lovers know, good fruit stands and farmers' market vendors also can be sources for nicely ripened stone fruits.
Also, when you grow your own fruit you can grow what you like - varieties that might not be conveniently available in the market.
Note: fruit that is very firm when purchased will often improve in texture, sweetness and flavor if left on the kitchen counter for a couple of days — or if placed in a paper bag at room temperature til it ripens.
For information about Dave Wilson Nursery's blind fruit tastings, see The Fruit Tasting Report.