See JBDS-1918 for steps to repro. This might be an izpack bug or an installer/uninstaller config bug, but either way the install folder - though empty - persists after installation.
If you double-click the uninstaller.jar, you'll end up with ~/jbdevstudio/ and ~/jbdevstudio/Uninstaller (both empty folders).
If you run the uninstaller from the icon (having tweaked it as follows first), you'll get just the ~/jbdevstudio folder – IF YOU HAVE EXPLORER OPEN TO THAT FOLDER. (If you don't then it purges the ~/jbdevstudio folder too.)
Target: "C:\Users\nboldt\jbdevstudio/Uninstaller\uninstaller.jar"
Start in: (leave blank)