"So you actually know nothing about MS SQL Server yourself, you just like it because... what?"
This is precisely the point I'm making - you say you want to learn, but you're not listening. I pointed out that I've worked with many other RDBMS in the past. Oracle is unnecessarily convoluted and proprietary just for the sake of trying to sell specialist training, though it is powerful and performant. MySQL is a joke - the very fact it even has (or had) to be bundled with a tool to fix broken datafiles is in itself farcicle, and as I said, in a production environment I saw it collapse for exactly this reason roughly every 3 - 6 months. I've never used DB2, but I've also never heard of anywhere using it in recent years either and frankly even their 3 case studies on their product site are companies I've never heard of. Maybe it's great, who knows, but it's just not a prominent option anymore, and with reduced prominent comes reduced training availability, reduced available skill sets on the market, reduced peer support when things go wrong.
So again, I like MS SQL server because it's stable unlike MySQL, it's easy to use, diagnose, maintain, and debug unlike Oracle, it offers centralised security configuration, as I've explained already, it integrates excellently not just with .NET but is widely and well supported in just about every language's DB framework out there.
On performance it can easily hold it's own against Oracle and PostgreSQL, I'll admit I have seen faster throughput on MySQL, but let's be clear, that's because MySQL cuts corners, and hence why it suffers from data integrity issues. If I wanted to sacrifice any of the ACID principles then I'd use a data storage system that intentionally does that and is designed for that from the outset, rather than because of failure of implementation - e.g. I'd look at a NoSQL solution if that fit my needs.
We use it for massive, massive databases, probably one of the highest use case scenarios you'll see without getting into Google index or Facebook use scale applications and here it does well too, it scales well, and it's easy to scale. We use it in a scenario where we're bound by contract in terms of response times, where any loss of reliability for even a short period can have literally millions of pounds of impact. Microsoft's support has been great - even on their existing closed source version they listen and make product changes based on our feedback, and that of other customers.
Others here have made the point that there's plenty of reasons to hate Microsoft, but SQL server isn't one of them, and that's absolutely true. Microsoft do a lot wrong, but products like Visual Studio, languages like C#, and products like SQL server are prime examples of things they absolutely do right.
I would suggest, rather than assuming you know it all and making sweeping comments about products you do not understand that you turn your thinking around and instead consider that something might be okay until you have reason to think otherwise. Because once again, by jumping to the conclusion that something is bad just because Microsoft, then hating people and childishly making them your foe because they explained why you're wrong, you're making a fool of yourself.
I could jump to conclusion too, I could assume that because you have a relatively high UID that you're probably relatively young and utterly naive, thinking you know better than those of us who have some extensive experience in the industry. I'm not going to do that though because I might be wrong - I'm going to give you the benefit of the doubt that you're just stressed, and venting your anger here or some such by trolling regardless of your circumstances, but ultimately it doesn't change the fact that you're wrong, and would do well to listen to all those explaining why if you ever want to get anywhere in this industry. A successful career has no room for zealotry and willful ignorance, you simply evaluate the options and take the best one for your use case, as many companies have found, hence the sales figures, that's quite often MS SQL server.