They will start like things because admired adult claims to like them, they will start to hate food because adult or other kids said it is disgusting. If you praise kid during activity, they are significantly more likely to seek that activity later and if you yell at them they will hate the activity itself. Adults are much better at sorting these influences out.

You can easily manipulate pre schoolers to dislike things and while it is a bit harder to make them like things, it is still relatively easy.

I think it's a social expectation based on selection bias. i.e. I dont think many people are capable of developing passion. That's not to say the average person doesn't have interests or are uninteresting, but few people go out of their way to focus on something that is internally constructive (autodidact, hobbies, art ) as opposed to externally constructive (e.g. tv, video games, internet). Another way to put it, an artist's distraction is their art.

Im speaking from an armchair, and as someone who discovered my passion at a young age (10). Throughout the following 18 years, I rarely met people who are >= mildly obsessed over something internally constructive (granted, I didnt go to college).