Why are you complaining about having to wear a bag over your head whenever you go out to pick up your prescriptions or meet your mistress, citizen? It's a small, reasonable step to go off the record. What is the alternative?
There's no reason why they couldn't to the same thing Mozilla does: a) have a pretty clear account thing for "sync", b) have a pretty clear page for opt/in out on what to sync, c) Have working self-host sync solution, d) have an open source sync solution so you can easily see what's going on, and how things are encoded/stored.