[aninteger]

Two reasons:

1. Visual Studio is not free. Yes there is Visual C++ express but for a while it didn't have C99 support because in general it was only a C++ compiler. I believe C99 support was added with VS2013.

2. It's just really nice to use the same compiler on Linux, BSD and Windows. This is possible with GCC and LLVM but not Visual C++.

Microsoft tools are not bad (in fact I like SQL server over MySQL or Postgres) but because they aren't cross platform it's very difficult to adopt. them.

[mrec]

Unless they've recently and very quietly changed their policy, the Express versions also don't support plugins.