The other part of the reason is your natural tendency to believe your tomatoes are better, because you put in all that work. Bias is a funny thing
"Home grown tomatoes" may be best when grown by good gardeners (i.e. some people are just better with kids, including their own) and the ideal environment (parks, museums, grandparents nearby). But it's not a universal truth.
A dedicated artisan can beat even an expert mass producer every time.