The problem is, we have very limited options, and Android is the most open of the currently available cellphone OSes (Meego and Symbian are kind of dead), and iOS and WP7 are not exactly very open.
The N9 phone is not really an upgrade to the n900. It has a slightly faster CPU, bigger screen and more RAM, but it loses the keyboard, FM transmitter, and notification light. It probably loses even the Flash 9.1.