> Microsoft has done an amazing amount of work writing and rewriting code to make cross platform open source .NET a real thing. All open licensed and developed in the open.

It's fitting you mention all the work Microsoft has done rewriting code. You're talking about .NET itself but I'm talking about the ecosystem, where Microsoft often does take others' projects and release their own version (the Windows package manager comes to mind), training the community to only trust things that come from them. Of course there was the recent famous example of Microsoft deleting public code so they could feature it in Visual Studio, but this tweet is typical of the attitude I've seen from the community: https://twitter.com/GeoffreyHuntley/status/14540569884432179...

This reply doesn't really have anything to do with your original comment. If Microsoft is producing a solid language / framework in the open and improving their product such that 3rd party "light-weight" libraries like Nancy are no longer necessary, why is that a bad thing?

In my opinion, while other ecosystems have exploded in complexity in recent years, the increasing simplicity and batteries-included nature of .NET is an appealing contrast.

That's my answer to your question about why you should be interested in .NET if you're not already in the ecosystem.

> If Microsoft is producing a solid language / framework in the open and improving their product such that 3rd party "light-weight" libraries like Nancy are no longer necessary, why is that a bad thing?

Because they are killing community made solutions by reimplementing the same solution and utilizing community's habit of favoring only MS software that they themselves engraved into that community throughout the years, even if original solution was better, thus closing the circle. They essentially kill the community around .NET themselves because instead of supporting projects like Avalonia, they reinvent the wheel(often ineptly) to ride on that 'Microsoft ecosystem' wave. The only exception to that that I know so far has been Polly that they pulled into .NET Core.

If it's all open source, why does it matter? My node_modules folders are a good example of why having thousands of individual open source fiefdoms is not always a good thing.

I don't think the Avalonia example is a good one either. Nobody talks about why Ruby on Rails doesn't support Sintara. In other ecosystems, every project is in competition. Why should .NET be singled out.

I think the argument that open source software can't compete with Microsoft is total bunk. If the alternative is competitive, it can succeed. Dapper has been around for over 10 years. Avalonia is "used by >170,000 companies, including 431 on the Fortune 500 list" according to their own website. Xamarin joining Microsoft is pretty much why we're talking about .NET 6 right now. Microsoft's first party solutions are really very good (in house or acquired). This is again why you might choose .NET over a more chaotic ecosystem.