The most compelling reason I have for choosing CLR and C# over virtually anything else (and ESPECIALLY Clojure and Scala) is availability (and consequently cost) of skilled resources. Availability both today, and 5 or 10 years from today, depending on the project or program.
In my world (Fortune 500) boutique tech carries inherent risk.
For me, Oracle is not as good of a stewart of Java as Microsoft is of .Net.
I wouldn't waste my time converting from a Java infrastructure to a .Net infrastructure and if I were a Linux shop, I probably would stick with Java for awhile, but if I'm already using Windows servers or have my choice today of using Windows only for the backend, I would definitely chose it because of the number of devs and network people available.
I know why you said Java. But I pretty expressly didn't, because BigCorp won't know or care why you said Java. Technical smugness doesn't change the fact that Scala and Clojure are exotic, and that exotic carries risk.
In my world (Fortune 500) boutique tech carries inherent risk.