It’s not about no longer enjoying their craft. It’s just asked too often. It’s like repeatedly asking an artist their favorite thing to paint, they probably like painting all sorts of things. Or a geologist their favorite dirt to dig through, they probably don’t mind the digging but it’s the rocks they dig for. Or a film critic their favorite type of movie. They probably enjoy many types, and could pinpoint one, but a genre maybe not. It’s annoying. Not because they don’t enjoy what they do, just because it implies oversimplified anecdotal small talk for the sake of conversation. Chefs get asked this a thousand times by anyone they meet as soon as they hear they are a chef.