The problem with PPA wasn't anything to do with the method it uses. Given enough announcement, discourse and investigation by the community; it's entirely possible that users in general would have accepted it.

However; Mozilla did something very wrong by deploying this without asking the greater community. Point blank. That's not good faith; and that did not allow for the community to go over the code and suggest fixes and express their concerns with how it works.

Instead Mozilla took the lead and decided it will exist; quietly. Without consulting the community. Given that this is how most companies turn selfish, that alarms MANY people who are knowledgeable about how Mozilla typically operates, and it undermines public trust in Mozilla.