Nested struct member has no access to the enclosing class data

[RivenTheMage]

On Monday, 6 August 2012 at 21:51:24 UTC, Andrej Mitrovic wrote:

> There is no "outer". A nested struct has the same access as a 
> nested
> static class, meaning no access to any outer members unless 
> they're
> static.

Is there somewhere I can read the rationale behind that decision?