Most of our problems with MEB have been tied to the WebSphere and SVN integration features. The devs have been working with the tools team to get it worked out, so I'm not in the details on each issue. But I was getting reports of "delayed for 2 hours due to MEB" pretty much daily from multiple projects and teams. The department as a whole, across ~40 developers, has viewed the upgrade as severely negative and it has sparked talks of switching to Eclipse and other tools.
I'd agree with you on the databases being orthogonal. I was just pointing out that the parent's point about .Net requiring SQL Server was factually incorrect. While I strongly prefer SQL Server because the tools that are included, and the 3rd party tools available, make certain aspects of software development, release management, and debugging sooooo much easier. Oracle has many similar tools, but again, the price is a tough pill to swallow, and in my experience, they don't have the same UX polish that MS has put together in the SQL Server tools. When the Free Toad fork went out of active development 10 years ago and it's still considered one of the better tools to work with Oracle through, it kinda says something about the quality of tools available to Oracle.
I believe you are correct on SharePoint, at least I've never implemented it on anything other than SQL Server, and giving it's reliance on in-document searching and the MS text search engine, I'd be very surprised to find out that it could run on a different back end.
There is an affinity as well between IIS and .Net. I believe you can run .Net sites off of Apache on Windows, but I would wager you would have a much lighter support community.
And while Mono and the MS Open initiative are breaking the affinity between .Net and Windows, that relationship will always exist. At this point though, I'm much less interested in WPF. Not because there is anything wrong with it (Honestly, a true vector based layout engine is soooo much better than dealing with flow based layout of HTML), but because the war is over, Web killed the desktop app. There are very few scenarios where a desktop app is still necessary, especially in the LOB environment that the majority of development is involved.
Don't get me wrong, Java is a great language. Not drinking the coolaid here. I'll jump to PHP or C++, or Java as the project requires. But Visual Studio is by far the strongest, most stable, and feature rich IDE available on the market.