Meh, I don't think you can simplify it to just passion. I think culinary involves a whole gamut of emotions and senses. A home cook can have all the passion in the world and 3 hours to make one dish for two people but that is not a fair comparison to a professional. Good food comes from multiple sources, cooking for friends and family, executing dishes using honed skills like time and detail management, stubbornness, hunger, you get the picture. My mother was never cooking our meals with "passion" but looking back they are some of the best food memories I have. I certainly don't have any passion when I come home late from working all day and throw something together to eat but it doesn't make my food taste worse. Don't get me wrong, I respect people who can have that level of passion for their cooking, it's just not my only motivating factor for it personally.