I am not an iOS developer, but my friends' two 11-year-olds have produced a few apps, without any formal training. Not polished, but they work. I don't have any other evidence that these two are extraordinary geniuses.

My impression is that iOS developer tools (and modern high-level tools generally) provide beginning developers with a much quicker path to producing highly visual applications than I had as beginning C programmer decades ago.

More visual feedback == more fun == more motivation to continue.