In the new D release why use free functions instead of properties?

[Gary Willoughby via Digitalmars-d-learn]

In the new D release there have been some changes regarding 
built-in types.

http://dlang.org/changelog.html?2.066#array_and_aa_changes
I would like to learn why this has been done like this and why it 
is desired to be free functions rather than properties?