Generally I'm against both "Your" and "My". A computer system is a tool, a storage, a servant or aide. When I use it, it is all by my command in some sense. So I consider this possessiveness in the interface unnecessary. I wonder if this is partly a personality-type thing? Maybe it's me :-)

That's covered at the top of the article. The author agrees with you.

The article is about when you should use my or your in form controls like upload dialogs.