I am writing a WPF app now, I don't think that's necessarily a bad thing. The issue I see with your example is that WPF as a platform went against just about everything your user needed.

   * Alienate users with a platform that's not compatible with their OS by default (OSX, Linux)

   * Alienate users with a platform that's not compatible with the multiple platforms you may be targeting (Tablet, Phone, Laptop, Desktop)

   * Require an extra step (e.g. Silverlight plugin) for users to run the app at all

That's why the LoB example is such a powerful testament to how WPF may stick around. You've got 'trapped' users (for better or worse) who will likely be forced on the Windows platform.