Microsoft neither love nor hate Linux - they just want to maintain their revenue stream
Microsoft are just a company and look after their own interests. Their business model still relies on users paying one off licence purchases or a subscription model (e.g. Office 36x). Embrace, Extent, Extinguish is still there. That is why Microsoft are adopting the Chromium engine - to try to stop the rush of people away from Edge. There is nothing remotely community minded in any of this. Having the Windows Subsystem for Linux (WSL) is not about being 'nice' to the open source community. It is about trying to stop developers moving away to Linux onto Linux for their own day-to-day usage. The same goes in porting SQL Server to Linux. Companies are leaving WIndows Server for Linux in droves for their high-end server usage. Porting SQL Server to Linux makes perfect sense in terms of trying to maintain a revenue stream. As this article says, it is neither good nor bad just common business sense.
Buying Github means Microsoft can maintain a small revenue stream from some of their bigger customers. That's just running a business. It does not mean Microsoft have changed their spots. What Nadella has done is to move with the times and moniterize other revenue streams (like Azure). Businesses that do not adapt do not survive. Any reasonable CEO knows that.
I run Linux on both desktop and server and it works for me. I am one of the few Linux users who bother to play games on Steam. Running Linux on a laptop would not work for anybody who relies on particular proprietary software (e.g. AutoCAD) that does not run on Linux. I fully understand that. For most home users and many businesses it would. This is a big threat to Microsoft's business model (although whilst there are so few PCs or tablets preloaded with Linux, it is not much of a threat at the moment!). Nadella understands this as well hence the need to win hearts and minds - otherwise as stated by others, Microsoft becomes just another cloud provider. Many hate him but in terms of keeping Microsoft relevent and afloat, I think Nadella is doing a reasonable job.