An update from Mozilla
https://blog.mozilla.org/en/products/firefox/update-on-terms-of-use/
They reworded stuff and responded to pretty much all of the issues that were raised
TL;DR: most likely corporate just did an awful, awful job at phrasing (unsurprisingly)
@odoben
I don't want Mozilla to "process" my data at all. The browser should be a tool that I use to interact with web sites and services. At no point after I download the broswer does Mozilla need to be involved.
Sync is different, whatever other services they offer, then it makes sense to require an agreement. Then Moz has legitimate cause and consent to process data on my behalf.
But basic browsing? There is no way Mozilla should ever see any of my data, let alone "process" it.