[eluser]ray73864[/eluser]
I can see how that would get out of hand rather quickly though, as it means you have to maintain code for multiple copies of the same module just in different themes folders.
even if you only stored the views in the themes folder it would still get out of hand very quickly.
probably one of the reasons why Joomla is overly bloated.
one of the advantages it does give you is the ability to theme each individual component of a module, but really, all the views in the modules folder should just be simple HTML that CSS can stylise.