I think it's largely a case of cargo-culting a Rails core decision made somewhat arbitrarily before Rails was even released (ie. config/database.yml).
Theoretically I suppose YAML is supposed to be a human-editable data format, but after trying to get translators to translate app strings in YAML format I decided that YAML is worthless as anything except an interchange format, and even there, primarily for Ruby because of its rich semantics.
Theoretically I suppose YAML is supposed to be a human-editable data format, but after trying to get translators to translate app strings in YAML format I decided that YAML is worthless as anything except an interchange format, and even there, primarily for Ruby because of its rich semantics.