Probably a combination of iPhone's traction and the general negative sentiment towards Java. I personally feel Objective-C is a good fit for mobile development, because its so easy to drop down to C at any time. And I'm sure I'm not the only one who thinks its conceptually simpler than Java (The Obj-C all just C structs and functions under the hood).
I think it's general sentiment against Java, the language. Many I know, including me, have been there and don't want to go back. At the same time the JVM is a pretty interesting space for language runtime.