The Free Version contains the following features
Store quiz results in database
View summary of quiz results
Email each quiz result to admin
Create auto-response email to quiz takers
Customizable email content and subject line to quiz takers
Responsive design for mobile compatibility
Compatibility with all major browsers
Single-answer questions
The extended version contains:
Multi-response questions
Free input text boxes (one line of text)
Free input textareas (multiple lines of text)
Select boxes input type
Custom field text input
Custom field textareas
Add images and media to questions
Add images and media to answers
Email-only field for gathering user’s email address at end of quiz
Custom fields for gathering miscellaneous information at end of quiz (name, contact info, etc.)
Add custom field values to auto-response email
WYSIWYG editor on questions and answers
Create multiple quizzes
Display end user their score at custom URL
Display end user their answers at custom URL
Export results in CSV format
Delete results
Randomize question order
It sounds like you are punishing the plugin for having premium features instead of rating it based on whether it does what it says it does.