2 things: you have to manually install a Web browser. Under Debian, it is equally as easy to install Firefox as it is to install chromium and other competing browsers (no lock-in), and the big one: you are not compelled to pay for Debian like you are for Windows.
Not even remotely comparable. Firefox is not a product of Debian, and Debian is not nor ever has been in a "monopoly" position with respect to any market.
I think you know as well as everyone else that that's not the same thing. MS did not provide an option to uninstall IE, where debian literally has dozens of FF alternatives at your fingertips.
