This is definitely a failing of yaml. Though, I feel that generally it's the sort of thing you learn once the hard way, then it sticks with you pretty well.
Also I'm glad there are more anti-toml folks are out there, feels like I'm taking crazy pills when people say it is "simple" and "elegant". IMO it's uglier than old-school ini format - at least it's more strictly defined but that doesn't really sway me to convert