I agree with Chip Bennett, most people are installing plugins from their WordPress admin area, so they are less likely to go to wp.org and report if a plugin is broken.

How about the core includes an option for plugin authors to decide whether or not they would like users to give feedback upon uninstallation of the plugin. Plugins that participate in the program will display a feedback screen when a user deactivates their plugin.

This screen can show rating stars, broken or worked form. If a user clicks on a star a popup window opens asking them to leave their review.