The thing is, he's right isn't he. There is a learned helplessness that's a giveaway sign of a .NET developer. Have you ever tried to use a, say, SOAP service created by a .NET team? Sure they know how to hit the "export as web service" button, but they've no understanding of the underlying technologies - Schema, WSDL etc. .NET makes sure to hide that away from them. So when something doesn't quite work, or needs tweaking, they're lost.
And you can't get away with that in a startup environment, that's his point. It's all very well for Mr. Smug up there to make sweeping, uninformed statements about other languages, but look at the biggest most successful former startups - your Wikipedias and your Facebooks and whatnot: not one .NET shop there, the majority being PHP-based.
There's no such thing as "better" when it comes to programming languages, but there certainly is such a thing as "more suitable to a given problem". Programmers have a surprisingly hard time seeing that, hence the ensuing shitstorm.