> so a lot of those non-Microsoft software actually still run on Microsoft
As a FLOSS advocate myself, this matters less than you seem to imply. Microsoft is publicly traded, they'll pivot to goat herding if that's the way to maximize profit. So avoiding it is (imo) less important than avoiding their lock-in products. If Azure has little lock-in, might as well use it, icky as it may feel to me personally. It's not inherently anti-FLOSS, because Microsoft is not inherently anything.
> If we file a primary incident report to Microsoft, Seattle will be on the phone with us until it’s fixed. What Linux house will offer this service?
I think both Redhat and Canonical would love that business.
I'm not looking to argue as you seem to know what you're saying, but on the financial side, how many millions are spent on Windows, Office and other licenses every year? I'd say it's worth doing the math.