> Maybe because Mozilla collects a massive amount of "telemetry" on users, in a way that is personally identifiable, despite zero need for it to be so?

Please point out how to personally identify a telemetry user.

I am a Firefox engineer who uses telemetry data, and know of no way to personally identify any of my users. Well, one way -- you can voluntarily put your email or other info into a crash report, though I know there was some talk of stripping that text field out because it's so rarely useful and touching any potential PII is like touching hot lava.