That was not the only issue
1. Failure to Disclose it before distribution
2. Failure to Properly name or provide any support context to the Add In.
3. Using the "Studies" System designed to improve the technology and advance the web browser for this Adware "Easter egg" not really an Easter egg addin
4. Failure to Publicly Comment about it until a full 72 hours after concerns were raised
5. Deleting and Hiding Bug Reports about the Addin in Bugzilla
6. Failure to adequately respond, apologize, or explain why and how the Studies system was used to distribute this Adware, There blog post so far is woefully inadequate.
7. Failure to disclose what steps are being taken immediately to ensure the Studies system is not abused in this manner in the future
Should I go on? There were many many many failures here, which are compounded by the many other failures Mozilla has had over the last few years.