I don't think Bryan is being lax with history at all. In fact, he completely nailed it. The only points in your comment that I found persuasive, on the other hand, are that Windows is indeed becoming irrelevant, SQL Server probably has an edge over MySQL in some ways, and Exchange needs to die a quick death. The rest just doesn't fly.
Hatred for Microsoft doesn't exist any longer? Says who? I believe it runs much deeper and stronger than you realize. I haven't purchased a Microsoft product in well over a decade, and that "purchase" was a PC preloaded with an OEM license of Windows that I had no way of not buying. My loathing for Microsoft was sown over decades of the most user-hostile, winner-take-all, I-will-rip-off-your-head-and-shit-down-your-neck corporate culture I've ever witnessed. Bryan calling Microsoft "predatory" is being kind.
I'm not sure what "OS field that has been gaining serious traction for the last 3 or 4 years" refers to, but if you're talking about desktop computing, they are doing exactly the opposite of gaining traction: http://twitpic.com/a31jis They aren't just becoming irrelevant to the elite; Microsoft is rapidly becoming just plain irrelevant.
How does C#'s popularity debunk Bryan's entire argument? A lot of companies still use Windows (for now), which means a lot of people use C# to develop applications for those computers. I don't see how this debunks much of anything.
SQL Server is good. Is it better than MySQL in some ways? Sure. What are the chances I'd select SQL Server instead of PostgreSQL? Zero percent. So that's a false equivalence right there, but that's besides the point. The reason people use MySQL or PostgreSQL instead of SQL Server is that you don't need Windows. Why tie yourself to a user-hostile company that's only going to charge you ad infinitum upgrades for a malware-ridden operating system? Even if SQL Server were heads-and-shoulders above MySQL/PostgreSQL, people would avoid it because you can't get it without Windows.
As I said, Bryan really nailed this: you're either burned so badly by Microsoft that "hatred" doesn't even begin to describe your feelings, or you're apathetic because the world has moved on and Microsoft continues to pretend like they live in the 1990s. With Ballmer at the helm, steering Microsoft towards seemingly inevitable obsolescence, Microsoft appears destined to eventually join Wang, Sun, RIM, Nokia, and the other dead or soon-to-be-dead. It didn't have to end that way, but reaping what you sow is generally the way the world works.