Is this surprising? I work at Microsoft and all development machines have IE+Chrome+Firefox installed. Our products, like everybody else's, are required to work on all browsers.

Of course they are. I would be seriously worried of using M$ products if their developers still used IE for development. That said, I yearn the day that IE is happily buried in its own filth. No later than today I had spend 3 hours fighting unexpected IE behaviour. Sigh..

Yeah, but they can afford to do that now :). This is what you get when you are playing nice with all platforms.

IE/Chrome, Visual Studio/Sublime, ASP.NET/Node.js - who cares, just be a Microsoft developer and be happily productive.

Mostly becuase is sad to say, but mobile developers only test in Chrome these days, so MS is practicly being forced to use it.