The share button will embed your data in a url (Base64 Encoded JSON) that you can save or share with others. Your changes are also saved to local storage (use the Reset button to wipe that).
If you mean data harvesting for some sort of lead gen or analysis; absolutely not. I think this data is very private.
It is refreshing to see data not being collected for what is a free service. But as far as I know you are not collecting any personal information that may be used to identify a specific person.
Can you clarify more on why you think data collection here is unethical?