Re: perfectly reasonable?
A web site only ought to know the window size.
And perhaps not even that. But browsers have become far more than rendering engines; have become the thin clients of today.
Some people really do want to interact with devices through their browsers, want to be able to 'one-click upload' their health tracking dongle data and have it appear as a graph before their eyes. Browser manufacturers can either tell those users to fuck off or cater to their whims.