.NET is the most open, non-trivial ecosystem I have ever participated in. I experienced 2 different problems with .NET (back in 2.x/3.x days), and was able to have interaction with the actual MS developers on their Github issue page without any sort of bullshit overhead process. Within days, I saw traction on my comments and within months I saw PRs that ultimately resolved the issue I presented. The following year, I…
People aren't using "open" in this thread as a euphemism for "nice" or "open to help." There are a lot of nice, friendly, helpful people who work on very proprietary, very closed, intentionally non-interoperable software. It's alright for you to like them personally and to think their products are great, but maybe it's not alright for them to have critical software in Linux distributions, or for people to base their own businesses on that software without being mindful that when you do that they become a defacto partner.