There's diminishing returns on increasing column width; the human eye starts to get strained if reading columns wider than ~60 characters. If the increased page width is applied to design elements and increasing font size, sure. That's not so bad of an application.
However, the English language's z pattern is inherently vertical, meaning that a page should naturally have space on either side; forcing a window to fullscreen just to have a 33% column of text is asinine, and shows that the designer is a prick for thinking strictly for XP and Windows' maximize button.
You're right about Windows' "Maximize Everything" being weird, it seems more and more like it was a good stopgap for people switching over from DOS and needing all the pixels possible on a tiny screen. OS X's natural flow for page windows may get confused from time-to-time, but it's a much better solution for dealing with vertically-biased windows in a widescreen environment.
It's not necessarily something you notice. It gradually gets a bit more difficult once you start getting past that point. And you won't necessarily think "oh, this is so hard to read" either (at least at large-but-still-reasonable widths). It'll just end up being a factor you weigh (if not consciously) when deciding "okay, I've had enough with reading this" and go on to the next thing.
However, the English language's z pattern is inherently vertical, meaning that a page should naturally have space on either side; forcing a window to fullscreen just to have a 33% column of text is asinine, and shows that the designer is a prick for thinking strictly for XP and Windows' maximize button.
You're right about Windows' "Maximize Everything" being weird, it seems more and more like it was a good stopgap for people switching over from DOS and needing all the pixels possible on a tiny screen. OS X's natural flow for page windows may get confused from time-to-time, but it's a much better solution for dealing with vertically-biased windows in a widescreen environment.