I have a real issue when people start saying you need to chose a cloud provider based on if your an open source company, or Microsoft shop or some other characteristic. You should chose a provider based on your needs, their uptime record, choice of services, price, track record of killing services, ease of use. To say that if your open source you should go to Google is a ridiculous statement. I can see that if your a Microsoft shop you may have a preference for Microsoft, but at the same time all the top three offer a bunch of integrated services for windows so I wouldn’t make my cloud choice based on I’m a Microsoft shop therefore I need to go to azure. You are choosing your infrastructure provider, it has less to do with your application type but more to do with who runs their infrastructure better.