Mediocrity doesn't rule the .NET world. I've been a part of both worlds. There's very little difference, beyond the anti-MS sentiment. Generally, when guys like this get fed up, it's really just anti-MS sentiment.
His post isn't meaningful, insightful or interesting. It's poisonous. A community is what you make of it, and he's making it worse. We're better off if he leaves.
Frankly, I'm sick and tired of the negative folks, and it's a big part of the reason I never went along with the Alt.NET folks. The idea of bringing the agile methodology in, embracing SOLID, and bringing Open Source into the .NET community is all good, but not at the expense of the negativity they brought with it. You won't get people to follow with attitudes like that.