The operating system came out 9 years ago. Windows 8 was a massive misstep but they've righted the ship somewhat with 10.
There's two control panels bit in each update more functionality moves into the Windows 10 style control panel.
The calculator is just a flat styled application not sure why it's rediculus. But tbh I use Google, Excel or Wolfram to do my calculations rather than that app.
Features that Windows 10 has for usability. Well there's multiple desktops, small things like built in f.lux.
It's nice that you can set a device specific pin for your account. Though having a cloud based account like Android or iPhone may upset some.
Also there's excellent touch screen support as a lot of laptops these days support it. Unloke OSX. Sometimes it's just better to scroll using your hands.
There's a lot of things under the hood that make it faster and more secure.
There are downsides like Random reboots for updates.