I'd disagree with that based on the stereotype of windows users not caring about UI or not noticing the lack of things like smooth animations and awkward sizing.
I say that as a windows user and fan (I have a mac, but it's far from my favorite machine).
I also don't feel that mac is any better at managing two windows than Windows.
Microsoft has tried to improve the side-by-side window set-up with their hot spots, but I feel it is a fairly weak implementation, and even though they advertised the feature heavily in Windows 7, I doubt many people use it regularly.
I didn't mean to say that all windows users do this, or that users of other OSes don't do that, but based on my experience most of the people who work with just one maximized window are windows users.
I don't want to start an OS flamewar though, so I'm going to restate my guess as:
I'm guessing most of the wide screen "haters" are people who are used to the "one maximized app at the time" workflow.
I cant use an OS without the Window snap functionality of Windows 7/8. Just throw the windows into opposite corners and go. Every time I show people that feature I get a positive reaction but I guess I really have no idea how much they use it.
I use Windows and OS X on most days of the week, and Windows has never been that well suited for wide screen use, whereas OS X's window management makes it much easier to put screens side by side. I'm often doing this, and it's one of the biggest reasons I'm more productive on OS X. The idea that an app would take up my entire screen, unless it was something like a video editing app, is crazy to me.
A widescreen laptop monitor allows me to copy and paste data from an email into a spreadsheet for instance. Doing that on a 3:2 monitor would be maddening. I agree that for single window use, 3:2 is better for many things, but we don't really like in a single window model anymore.
I use both Windows 7 and OSX everyday. Windows 7's window management is so much better that, it makes me realize how much time I lose managing windows on OSX. The only logical explanation I can come up is that you don't know about snapping windows on Windows 7. Dragging a window to the left or right side of the screen (or with keyboard: Win+Left/Right) will tile it to that part of the screen.
One can say that he'd rather have a tiling window manager and an environment similar to the one he'll deploy in rather than dealing with various incompatible build systems and the strange mix of BSD environment presented in Mac OS X.
That is to say, all OS suck; and we should not compare dick sizes, as we would all lose.
window management is indeed better designed on windows (since 7) which makes your parent poster's claim a bit unsubstantiated, but thinking about it a little more there is something to it: Windows applications, especially since the ribbon UI pattern has emerged, are often specifically designed such that you need them to run in fullscreen. Try using office on 950px width and you know what I mean - you simply can't get to lots of control elements comfortably without the full screen width. Mac software on the other hand has always been optimized for multiple non modal panels, still carried over in the prominent info window even in consumer apps. You can place that thing wherever you want. For power users this is very good because they can position these windows as close as possible to the content they want to edit, scroll the window behind without loosing focus (still not a standard windows feature) and do a series of operations minimizing mouse movement and clicks, since a panel of similar operations as their last one stays open. This as well as the always accessible main menu is what allows users to play around width the width of windows.
If only window management and multi screen support were as good as the one on windows - it would pretty much be a perfect classic desktop environment.
I say that as a windows user and fan (I have a mac, but it's far from my favorite machine).
I also don't feel that mac is any better at managing two windows than Windows.
Microsoft has tried to improve the side-by-side window set-up with their hot spots, but I feel it is a fairly weak implementation, and even though they advertised the feature heavily in Windows 7, I doubt many people use it regularly.