If you're going to build via cli, you'll already be using 'nuget restore'[1] as part of a bat file or whatever in your build.
And you'd have to be pretty belligerent of VS to use a cli to create a .Net project instead of clicking 'File > New > Project...'. Although the amount of crap they add in to a asp.net project these days is phenomenal. You spend 20 minutes deleting all the junk they've added.
It just seems to be a simplification. In all honesty the article doesn't actually say anything really about why we should use it.
No, the article makes that rather clear: You don't have VS on other platforms. This is a cli interface for every supported OS/platform, while you had to use msbuild/xbuild previously (and a couple of things on top, nuget being one).
Obviously you can do everything .Net related already - if you're sitting in VS on Windows.
csc.exe did not. In ye olde days, you'd have to use nmake or similar (batch files - gahh!) to manage compiling applications that had multiple source files.
