I'm surprised you think this, as I've been surprised in the other direction :)

I'm mostly from a Windows and .NET background, but I'm reasonably comfortable in Linux too, and I've been surprised at the breadth of support for Linux and traditionally non-Windows languages, such as Python and Node.js.

As an example, take the docs for what must be one of their most used services, App Services: https://docs.microsoft.com/en-gb/azure/app-service/

Right on the front page there are quickstarts for .NET, sure - but also Node.js, PHP, Python, Java...

Some of their newer services are even Linux first, such as AKS!