Takes hours to install

I think it's designed to handle windows-size code base (50 MOC)
so even for "hello world" you'll have a lot of junk you'll never need

C# made me appreciate Java desu.

Why would someone need an IDE?

Can be pretty nice to have everything in one program.

That's it? compiling a C program or running scripts from VIM is easy, and you get all the highlighting + autocomplete.

I'm a spacemacs user myself, since I like having a single editor for everything, instead of a bunch of IDEs, but it all comes down to personal preference.

I get all the personal preference thing, but Visual Studio is a huge program and too bloated.

VS sucks, but KDevelop, QtCreator, Eclipse and Code:Blocks are decent IMO.

When you just want to write C/C++ but you don't know which box to tick so you install everything ever created. At least I have Unity now

For like 3 months now VS Installer let's you update VS to sub-major releases without needing to close the software itself.Obviously when you install new components or important extensions the software itself needs to restart because everything needs to be re-initialized.
VS is used in the most complex and biggest projects ever because it's somewhat reliable and has a lot of features that may not be used by normal users like you.
Big games like GTA V or complex software like Unity, Unreal,etc. are not written in boomer software like vim,emacs or nano.