It is dependent on a specific indentation format which is one thing I dislike about it. But if you configure your vim or whatever editor you use to properly indent YAML files you should have few issues with fragility.
Even with indentation problems, the time saved in not typing curly brackets, extra quotation marks, and commas, and the time saved in not having to visually parse these when reading YAML more than makes up for the occasional data structure bug caused by bad indentation.
Even with indentation problems, the time saved in not typing curly brackets, extra quotation marks, and commas, and the time saved in not having to visually parse these when reading YAML more than makes up for the occasional data structure bug caused by bad indentation.