I agree that productivity trumps cost. Its clear that .NET and the rest of the MS stack (if you choose to use them) absolutely do provide value.

But so do Rails / Grails / Java / Django / MySQL / PostgreSQL / Redis / Cassandra / Linux / et al., with zero licensing cost (or headache), better deployment flexibility, and the ability to customize them or fix any bugs that are in your way.

Certainly arguments can be made one way or the other on which stack provides more value in terms of time/labor/skills/flexibility, etc.

That said, the article was much to quick to dismiss cost as a factor due to BizSpark.