Struct initializers: Rationale for limitations

[dsimcha]

According to the spec for static initialization of structs:

The static initializer syntax can also be used to initialize non-static
variables, provided that the member names are not given. The initializer need
not be evaluatable at compile time.

What's the rationale for requiring that member names are not given?  This
seems like an incredibly useful feature that's being omitted for no apparent
reason.