The INI example is in response to "Don't make your users created multilayered objects". Personally, I cannot stand TOML, but there's no accounting for taste.

I think the significant whitespace is a pragmatism thing. If you're already doing it, do it consistently, if you're already doing it consistently do you really need brackets? The answer is no, and the added bonus is you (and everybody else) is forced to do the whitespace consistently. I'll take a consistently formatted codebase over inconsistencies any day!