There is no technical reason for this. It's just that we have not gotten this far yet.
That request is getting increasingly popular, however, so it looks like we'll get to it soon. In the meantime you could vote for that feature here - http://justdecompile.uservoice.com/forums/113277-justdecompile-feature-suggestions/suggestions/2632513-enable-create-project-fo-visual-basic-also
the Telerik team