Are you sure this is the reason? Our company uses Microsoft OS and office tools across the board. But when it comes to development most of our work is done in linux. A version of Visual Studio for Mac would make no difference.
Your company seems to be very atypical. At least here in Brazil, most people who used to develop in Visual Basic for Windows have moved to ASP and then to ASP.NET for web applications. Of those who felt tempted to use Java, many moved to C#, which is very Java-ish.
Not all corporate developers are good developers. Managing good developers is hard and managers prefer the more predictable, cheaper, average ones. Sadly.
