I agree with your statement. I wouldn't trust MS to run FreeBSD on their hardware at all. What if they throttle the performance of FreeBSD without you ever knowing it? Embrace and extinguish has always been their motto.
The only "evil" that I've experience with Linux is that Microsoft has price parity between Windows & SUSE Linux on Azure, which is competitive for Windows but a premium price for SUSE Linux (and an extra premium price for RedHat Enterprise).
Linux without a support contract should always be cheaper than Windows because that's the reality with the license costs. Microsoft's competitors are far cheaper for Linux VMs, but if you're willing to pay the premium it runs fine on Azure, and performs better than Windows on the same hardware (although the gap is smaller if you run Windows headless, using Windows Core).
Every time our IT Director talks about Azure I want to cringe, our infrastructure is relatively static and only grows - so it's straight up MORE expensive to put anything there (and this factors in power and cooling to the datacenter).
I wouldn't trust an operating system company that runs a "server farm" where they have their own OS and competitors. Why would Microsoft run their competition on their own hardware & data centers? If Azure breaks off from MS and becomes an independent company, OS agnostic, then maybe they can win my trust back.
I like Azure & would only use it for MS based OS, DB etc. I would never run, nor would I recommend any other OS running on Azure, ever. There are other "server farm" vendors that I can choose from for non MS based cloud computing.
Agreed on other points made on this thread regarding pricing, though.