Reposted from my comment on the other post:

Firefox is the only fully open source direct-to-consumer product that operates at such a large scale, and there is a ton of regulatory pressure on them to be as forthright as possible in stuff like the tos and privacy policy, and since they’re the only one they can’t learn from others mistakes.

Combine that with legalese sounding scary and Mozilla not being great at communication (they’re trying though, remember we heard about this from a blog post) and you get the current situation.