Substitute whatever you want for Rails, and ASP.NET will still have a better ROI for any given single application, and potentially (probably, in fact) for all their apps even if you artificially ignore switching costs.

We don't build apps in ASP.NET. We use Ruby. But we do a lot of security work for people with ASP.NET, are knee-deep in a lot of ASP.NET dev teams, and the things ASP.NET does for enterprise apps are not "kool-aid".