The fact that you think widgets are those things on the panel shows how far behind OSX is. Hint: the desktop itself is a widget (in non-braindead implementations of the desktop paradigm).
The problem wasn't what I thought they were, the problem was that you didn't define what you thought they were. Lots of DEs have various things named "widgets." You were, and still are, ambiguous.
A window list is any object which gives you a listing of open windows/applications. The dock is one, the windows taskbar is one. They can have many shapes and properties. Some are appropriate for many open windows, some are better for the case of few open windows. The separation of applications in activity groups with their own sets of widgets is the only way of covering all use cases (until brain-machine interfaces). In fact, if you do presentations frequently, it is idiotic that you need to adjust power management each time.
Yes, that's what I figured you meant by window lists. I find no use for them. I don't use the Dock. I have it on autohide. I use Mission Control and Exposé to do all my window management, and it works great (for me). I still don't know what you mean by "widgets," so I don't follow you there. You seem to have a habit of typing a lot of words without actually saying anything. I also don't have a damn clue what you're talking about with regards to "power management." How on earth do you need to "adjust power management each time"? What exactly are you adjusting, and what are you defining as a "time"?
Bottom line, OS X is not a good DE. It is OK and extra shiny. But it is in no way the epitome of user interface design. And the WM sucks donkey balls (no always on top, no per-application user-defined rule sets, no per-application transparency, no magnetic borders, no auto-maximisation, no window shading, haphazard window placement, dodgy resizing, absurd placement and size limits on windows). The menu bar on top? would be a good idea it it could deal with a second screen in a not-stupid way. Don't get me started on Finder and the Dock.
No, the bottom line is that, in your opinion, OS X is not a good DE. Lots of people, including me, disagree with you. What is that you find so superior, then? I've used a lot of DEs and WMs, and nothing has ever come close to OS X. Let's go through your list of stupid little things and try to figure out what you're on about, shall we?
Yes, that's true, but I'd be willing to bet you 99.9% of people don't give a shit. I know I don't. I find it endlessly annoying, actually.
No per-application user-defined rule sets
What? Rules for what? Position and sizes stay the same. Which Space they're located in is remembered. I don't know what you're talking about.
No per-application transparency
Yes, there is. I don't know where you got this notion. OS X has always done this.
I'm guessing you mean window snapping? Some apps do it, and it's a standard Cocoa feature; you can download small tweaks that enable it system-wide.
I'm guessing you're referring to the Zoom button. By default, it makes the window the size of the content within it. I don't know why anyone would ever want to make a window take up more space than it needs, but all you have to do is hit Zoom twice.
You mean the thing where it rolls up into the title bar? People seriously use that still? Why?
Haphazard window placement
What does this even mean? You can put windows wherever you want, and unless you set it otherwise, it will stay there and be restored there even between application restarts. Seems like something you added just to add, but which doesn't actually mean anything.
What? What's wrong with the resizing? How is it any different from any other DE? It works fine for me, and everyone else, since 1984. The lower right is the standard place to grab, but you can do it from any edge or corner. This is exactly the same as every other thing I've used, or better.
Absurd placement and size limits on windows
Didn't you already say this? "Haphazard window placement"? How is this different? What're the size limits? I've never found any.
So, to summarize, some of them are just plain wrong, some of them really have no merit and/or meaning, and most of them are eye candy things that don't actually add any functionality. It sounds like you're 16.
As for the menubar on top, it's a matter of taste. Fitt's law prefers it since it's always in a known location; you can just throw the mouse to the top of the screen and you're at the menubar. I prefer the top menubar, and most switchers I've met either prefer it or don't care either way. As for multiple monitors, I use dual monitors on a Mac every day at work, and it's just fine. The menubar stays on the main screen, just like the gnome panel has always done for me in dual monitor Linux setups. But again, this is clearly a preference. You can't speak for anyone except yourself.
The Finder is just fine these days. It had bugs, like every other app ever, but I haven't had any problem with Finder since Tiger. As for the Dock, well, it is what it is. I don't think it's a particularly good "window list," but I don't want one anyway. It work just fine as an application launcher though.
So, bottom line is that you don't like OS X's GUI in general, and that's fine, but you certainly can't argue that as an objective point of view against some universal laws of Everyone Prefers What SomeKDEUser Prefers. You have your likes, and everyone else has theirs. End of story.