When a user votes a plugin as broken, they must also say what is broken or not working before their vote is valid.
Often a plugin won't work because of the users theme is missing hooks like wp_head() and wp_footer(), which has been standard since v2.1, or that their theme is badly configured placing these elements at the incorrect places.
Does that give them the right to anonymously shit on the developer who has taken the time to make a working product?
It would be way better to force a "broken" vote to also include a report of what is screwed up and sent back to the owner of the Plugin.
It would also be good to force a report when people vote down a plugin with 1 or 2 stars. Again the developer needs that feedback.