Because although owning a basic Windows 10 laptop, I can probably count the number of times I've used it in the last twelve months on both hands.
Then my Windows 7 work laptop choked on March and April patches, repeatedly got stuck in restart loops, and ended up coming back to me with Microsoft's latest turd-polishing effort. It took a few days to get relatively comfortable, but so far most things have been within reach and I've only used delegated permissions to hide the default folders in Explorer (Desktop, Documents, Downloads, Music, Pictures, Videos and... 3D Objects? Microsoft's getting far too cosy with pushing this kind of crap in enterprise releases -- ditto the Xbox app being included, which seems like it would've been politically unacceptable in a business operating system a few years ago). As we don't save onto local devices, having them showing at all times under This PC above drives and mapped shares is wasteful. Microsoft has kept moving goalposts which means that the configuration is stored under HKLM rather than HKCU (sadly it'll probably change again in future).
The poor colour contrast was the thing I was most worried about, but I've managed to avoid making a nuisance of myself with escalated complaints about eye strain using an accent colour of RGB 180, 190, 200 (hex #B4BEC8) applied to the taskbar, title bars and with transparency effects turned on -- there's just enough differentiation between other visible elements, and as a bonus the colour itself is something that could be described as Imperial Guard grey. Windows calls it "ice blue" which is rather fitting for Valhallan 597th fans. Basically it allows white or black text to be overlaid by the OS (though the transparency helps) and readable.
If you can't control wallpaper, by the way, you may still be able to use the "other options" screen that's currently under "ease of access" in Settings to hide it for a plain black background, but I find this too much contrast.
The start menu is virtually unusable, partly due to our organisation opting to prevent users from pinning tiles (not 100% sure why -- I think because of the live tile functionality, although that can be disabled specifically through group policy) -- so you'd have a purely alphabetic list or have to type to launch *everything* and the workaround commonly in use is putting shortcuts on the desktop for all main applications. Fortunately Windows 10 still has taskbar toolbars, so you can collect shortcuts into a folder and add them there, and get a menu if you don't mind the click area being reduced to a small arrow -- but after a week or two it becomes part of muscle memory to click to the right of the start button. You could also use Microsoft's junction tool to add folders for C:\ProgramData\Microsoft\Windows\Start Menu (all users) and C:\Users\<User>\AppData\Roaming\Microsoft\Windows\Start Menu\Programs if that's an option and of use, but a simple list plus type-to-run with the actual start menu is probably enough for most people (or in less constrained environments, there are options such as Classic Shell or Start10, even if CS dev is in flux).
Let's talk about something positive, eh? I was surprised there is some of that with Windows 10. Windows 7 introduced a feature Microsoft called "snap" -- dragging a window against either side of the screen to resize it to half the screen width (and as an incidental benefit, a weak vertical lock). This became something I use constantly and expect to see in any desktop environment.
Windows 10 includes some extra related features. They may have been in Windows 8, 8.1 or 8.1 Update and they may not have been in the initial release of Windows 10. It's not like I've been paying attention. But they definitely make me not miss Xfce quite as much during office hours, and are the sort of window management features that makes Windows justify being called Windows.
You can drag to corners to take up a quarter of the available space. Optionally use a snap action to position two windows at once (I don't particularly like this). Snap into gaps. Resize two snapped windows by dragging on the point at which they meet (which must be essential on tablets but is quite handy on a proper monitor too -- and can be overridden by holding down Ctrl whilst dragging).
There's also a passable implementation of virtual desktops, although it seems to lack keyboard shortcuts to move windows between desktops at the moment. However, Win+Tab and Ctrl+Win+left and right are pretty handy with two or more desktops defined, and useful when you've got various windows already open but someone's interrupting with a query that involves opening more. Office apps seem to be a bit badly behaved and desktop-hop, but overall a plus.
Bonus tip: Microsoft is trying to push Powershell and has removed the 'Open command prompt here' shift-right-click menu item from Explorer. Tap Alt+D or click into the address bar, type 'cmd' and hit Return to get a prompt in the directory shown.