- Embracing Linux. Beyond what's mentioned in the article, there's the Windows Subsystem for Linux, and the new Terminal app. Being able to run Ubuntu (or whichever distribution) natively on a windows machine, accessing the same file system, is huge for developers. The new Terminal app will make interacting with it even better.
- IDE dominance. Visual Studio (classic) combined with the .NET environment languages is very, very powerful. Visual Studio Code has taken web development by storm. A lot of what makes these two so powerful is Intellisense, which is extremely good at what it does. Compare this with XCode.
- Premium first party hardware. The Surface line of laptops / 2-in-1s / etc is at least as good as the recent Macbook Pros. They also innovated in an actually useful way (the detachable tablet on the Book), as compared to the developer-hostile "innovations" from Apple (replacing the escape key with a skinny phone, a universally reviled keyboard, etc)
I really have to give Nadella credit for the way this has all been orchestrated.