I have attached an example of Google Plus with the App Screenshot and Sitemap side by side to help explain my question.
The example has "Home" at the highest level.
Why isn't "Home" at the same level as the other Nav links? I understand you land on "Home" first, but that shouldn't matter, it's still on the same level right?
Your reasoning would be much appreciated.
Because sitemaps are originally created for web crawlers, like the one from Google, for them to better navigate through the site. Once crawler comes to home page, it examines and visits every link, and then on that links search for new one and so on..
Thing is homepages logically have most of the content and most of the links on website, so it is fastest point from where crawler can reach all other sublinks and content on site.
A sitemap is a diagram of navigation between pages on the site.
Since users are expected to arrive at the homepage first and then navigate to other pages from this page it is always above all other pages.
However, the fact is, a user can arrive at any page on your site first so there's an argument that all pages should be equally placed but that wouldn't be easy to understand or draw.